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Source file src/reflect/all_test.go

Documentation: reflect

  // Copyright 2009 The Go Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style
  // license that can be found in the LICENSE file.
  
  package reflect_test
  
  import (
  	"bytes"
  	"encoding/base64"
  	"flag"
  	"fmt"
  	"io"
  	"math"
  	"math/rand"
  	"os"
  	. "reflect"
  	"runtime"
  	"sort"
  	"strconv"
  	"strings"
  	"sync"
  	"sync/atomic"
  	"testing"
  	"time"
  	"unicode"
  	"unicode/utf8"
  	"unsafe"
  )
  
  var sink interface{}
  
  func TestBool(t *testing.T) {
  	v := ValueOf(true)
  	if v.Bool() != true {
  		t.Fatal("ValueOf(true).Bool() = false")
  	}
  }
  
  type integer int
  type T struct {
  	a int
  	b float64
  	c string
  	d *int
  }
  
  type pair struct {
  	i interface{}
  	s string
  }
  
  func assert(t *testing.T, s, want string) {
  	if s != want {
  		t.Errorf("have %#q want %#q", s, want)
  	}
  }
  
  var typeTests = []pair{
  	{struct{ x int }{}, "int"},
  	{struct{ x int8 }{}, "int8"},
  	{struct{ x int16 }{}, "int16"},
  	{struct{ x int32 }{}, "int32"},
  	{struct{ x int64 }{}, "int64"},
  	{struct{ x uint }{}, "uint"},
  	{struct{ x uint8 }{}, "uint8"},
  	{struct{ x uint16 }{}, "uint16"},
  	{struct{ x uint32 }{}, "uint32"},
  	{struct{ x uint64 }{}, "uint64"},
  	{struct{ x float32 }{}, "float32"},
  	{struct{ x float64 }{}, "float64"},
  	{struct{ x int8 }{}, "int8"},
  	{struct{ x (**int8) }{}, "**int8"},
  	{struct{ x (**integer) }{}, "**reflect_test.integer"},
  	{struct{ x ([32]int32) }{}, "[32]int32"},
  	{struct{ x ([]int8) }{}, "[]int8"},
  	{struct{ x (map[string]int32) }{}, "map[string]int32"},
  	{struct{ x (chan<- string) }{}, "chan<- string"},
  	{struct {
  		x struct {
  			c chan *int32
  			d float32
  		}
  	}{},
  		"struct { c chan *int32; d float32 }",
  	},
  	{struct{ x (func(a int8, b int32)) }{}, "func(int8, int32)"},
  	{struct {
  		x struct {
  			c func(chan *integer, *int8)
  		}
  	}{},
  		"struct { c func(chan *reflect_test.integer, *int8) }",
  	},
  	{struct {
  		x struct {
  			a int8
  			b int32
  		}
  	}{},
  		"struct { a int8; b int32 }",
  	},
  	{struct {
  		x struct {
  			a int8
  			b int8
  			c int32
  		}
  	}{},
  		"struct { a int8; b int8; c int32 }",
  	},
  	{struct {
  		x struct {
  			a int8
  			b int8
  			c int8
  			d int32
  		}
  	}{},
  		"struct { a int8; b int8; c int8; d int32 }",
  	},
  	{struct {
  		x struct {
  			a int8
  			b int8
  			c int8
  			d int8
  			e int32
  		}
  	}{},
  		"struct { a int8; b int8; c int8; d int8; e int32 }",
  	},
  	{struct {
  		x struct {
  			a int8
  			b int8
  			c int8
  			d int8
  			e int8
  			f int32
  		}
  	}{},
  		"struct { a int8; b int8; c int8; d int8; e int8; f int32 }",
  	},
  	{struct {
  		x struct {
  			a int8 `reflect:"hi there"`
  		}
  	}{},
  		`struct { a int8 "reflect:\"hi there\"" }`,
  	},
  	{struct {
  		x struct {
  			a int8 `reflect:"hi \x00there\t\n\"\\"`
  		}
  	}{},
  		`struct { a int8 "reflect:\"hi \\x00there\\t\\n\\\"\\\\\"" }`,
  	},
  	{struct {
  		x struct {
  			f func(args ...int)
  		}
  	}{},
  		"struct { f func(...int) }",
  	},
  	{struct {
  		x (interface {
  			a(func(func(int) int) func(func(int)) int)
  			b()
  		})
  	}{},
  		"interface { reflect_test.a(func(func(int) int) func(func(int)) int); reflect_test.b() }",
  	},
  }
  
  var valueTests = []pair{
  	{new(int), "132"},
  	{new(int8), "8"},
  	{new(int16), "16"},
  	{new(int32), "32"},
  	{new(int64), "64"},
  	{new(uint), "132"},
  	{new(uint8), "8"},
  	{new(uint16), "16"},
  	{new(uint32), "32"},
  	{new(uint64), "64"},
  	{new(float32), "256.25"},
  	{new(float64), "512.125"},
  	{new(complex64), "532.125+10i"},
  	{new(complex128), "564.25+1i"},
  	{new(string), "stringy cheese"},
  	{new(bool), "true"},
  	{new(*int8), "*int8(0)"},
  	{new(**int8), "**int8(0)"},
  	{new([5]int32), "[5]int32{0, 0, 0, 0, 0}"},
  	{new(**integer), "**reflect_test.integer(0)"},
  	{new(map[string]int32), "map[string]int32{<can't iterate on maps>}"},
  	{new(chan<- string), "chan<- string"},
  	{new(func(a int8, b int32)), "func(int8, int32)(0)"},
  	{new(struct {
  		c chan *int32
  		d float32
  	}),
  		"struct { c chan *int32; d float32 }{chan *int32, 0}",
  	},
  	{new(struct{ c func(chan *integer, *int8) }),
  		"struct { c func(chan *reflect_test.integer, *int8) }{func(chan *reflect_test.integer, *int8)(0)}",
  	},
  	{new(struct {
  		a int8
  		b int32
  	}),
  		"struct { a int8; b int32 }{0, 0}",
  	},
  	{new(struct {
  		a int8
  		b int8
  		c int32
  	}),
  		"struct { a int8; b int8; c int32 }{0, 0, 0}",
  	},
  }
  
  func testType(t *testing.T, i int, typ Type, want string) {
  	s := typ.String()
  	if s != want {
  		t.Errorf("#%d: have %#q, want %#q", i, s, want)
  	}
  }
  
  func TestTypes(t *testing.T) {
  	for i, tt := range typeTests {
  		testType(t, i, ValueOf(tt.i).Field(0).Type(), tt.s)
  	}
  }
  
  func TestSet(t *testing.T) {
  	for i, tt := range valueTests {
  		v := ValueOf(tt.i)
  		v = v.Elem()
  		switch v.Kind() {
  		case Int:
  			v.SetInt(132)
  		case Int8:
  			v.SetInt(8)
  		case Int16:
  			v.SetInt(16)
  		case Int32:
  			v.SetInt(32)
  		case Int64:
  			v.SetInt(64)
  		case Uint:
  			v.SetUint(132)
  		case Uint8:
  			v.SetUint(8)
  		case Uint16:
  			v.SetUint(16)
  		case Uint32:
  			v.SetUint(32)
  		case Uint64:
  			v.SetUint(64)
  		case Float32:
  			v.SetFloat(256.25)
  		case Float64:
  			v.SetFloat(512.125)
  		case Complex64:
  			v.SetComplex(532.125 + 10i)
  		case Complex128:
  			v.SetComplex(564.25 + 1i)
  		case String:
  			v.SetString("stringy cheese")
  		case Bool:
  			v.SetBool(true)
  		}
  		s := valueToString(v)
  		if s != tt.s {
  			t.Errorf("#%d: have %#q, want %#q", i, s, tt.s)
  		}
  	}
  }
  
  func TestSetValue(t *testing.T) {
  	for i, tt := range valueTests {
  		v := ValueOf(tt.i).Elem()
  		switch v.Kind() {
  		case Int:
  			v.Set(ValueOf(int(132)))
  		case Int8:
  			v.Set(ValueOf(int8(8)))
  		case Int16:
  			v.Set(ValueOf(int16(16)))
  		case Int32:
  			v.Set(ValueOf(int32(32)))
  		case Int64:
  			v.Set(ValueOf(int64(64)))
  		case Uint:
  			v.Set(ValueOf(uint(132)))
  		case Uint8:
  			v.Set(ValueOf(uint8(8)))
  		case Uint16:
  			v.Set(ValueOf(uint16(16)))
  		case Uint32:
  			v.Set(ValueOf(uint32(32)))
  		case Uint64:
  			v.Set(ValueOf(uint64(64)))
  		case Float32:
  			v.Set(ValueOf(float32(256.25)))
  		case Float64:
  			v.Set(ValueOf(512.125))
  		case Complex64:
  			v.Set(ValueOf(complex64(532.125 + 10i)))
  		case Complex128:
  			v.Set(ValueOf(complex128(564.25 + 1i)))
  		case String:
  			v.Set(ValueOf("stringy cheese"))
  		case Bool:
  			v.Set(ValueOf(true))
  		}
  		s := valueToString(v)
  		if s != tt.s {
  			t.Errorf("#%d: have %#q, want %#q", i, s, tt.s)
  		}
  	}
  }
  
  var _i = 7
  
  var valueToStringTests = []pair{
  	{123, "123"},
  	{123.5, "123.5"},
  	{byte(123), "123"},
  	{"abc", "abc"},
  	{T{123, 456.75, "hello", &_i}, "reflect_test.T{123, 456.75, hello, *int(&7)}"},
  	{new(chan *T), "*chan *reflect_test.T(&chan *reflect_test.T)"},
  	{[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}"},
  	{&[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "*[10]int(&[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})"},
  	{[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}"},
  	{&[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "*[]int(&[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})"},
  }
  
  func TestValueToString(t *testing.T) {
  	for i, test := range valueToStringTests {
  		s := valueToString(ValueOf(test.i))
  		if s != test.s {
  			t.Errorf("#%d: have %#q, want %#q", i, s, test.s)
  		}
  	}
  }
  
  func TestArrayElemSet(t *testing.T) {
  	v := ValueOf(&[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}).Elem()
  	v.Index(4).SetInt(123)
  	s := valueToString(v)
  	const want = "[10]int{1, 2, 3, 4, 123, 6, 7, 8, 9, 10}"
  	if s != want {
  		t.Errorf("[10]int: have %#q want %#q", s, want)
  	}
  
  	v = ValueOf([]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})
  	v.Index(4).SetInt(123)
  	s = valueToString(v)
  	const want1 = "[]int{1, 2, 3, 4, 123, 6, 7, 8, 9, 10}"
  	if s != want1 {
  		t.Errorf("[]int: have %#q want %#q", s, want1)
  	}
  }
  
  func TestPtrPointTo(t *testing.T) {
  	var ip *int32
  	var i int32 = 1234
  	vip := ValueOf(&ip)
  	vi := ValueOf(&i).Elem()
  	vip.Elem().Set(vi.Addr())
  	if *ip != 1234 {
  		t.Errorf("got %d, want 1234", *ip)
  	}
  
  	ip = nil
  	vp := ValueOf(&ip).Elem()
  	vp.Set(Zero(vp.Type()))
  	if ip != nil {
  		t.Errorf("got non-nil (%p), want nil", ip)
  	}
  }
  
  func TestPtrSetNil(t *testing.T) {
  	var i int32 = 1234
  	ip := &i
  	vip := ValueOf(&ip)
  	vip.Elem().Set(Zero(vip.Elem().Type()))
  	if ip != nil {
  		t.Errorf("got non-nil (%d), want nil", *ip)
  	}
  }
  
  func TestMapSetNil(t *testing.T) {
  	m := make(map[string]int)
  	vm := ValueOf(&m)
  	vm.Elem().Set(Zero(vm.Elem().Type()))
  	if m != nil {
  		t.Errorf("got non-nil (%p), want nil", m)
  	}
  }
  
  func TestAll(t *testing.T) {
  	testType(t, 1, TypeOf((int8)(0)), "int8")
  	testType(t, 2, TypeOf((*int8)(nil)).Elem(), "int8")
  
  	typ := TypeOf((*struct {
  		c chan *int32
  		d float32
  	})(nil))
  	testType(t, 3, typ, "*struct { c chan *int32; d float32 }")
  	etyp := typ.Elem()
  	testType(t, 4, etyp, "struct { c chan *int32; d float32 }")
  	styp := etyp
  	f := styp.Field(0)
  	testType(t, 5, f.Type, "chan *int32")
  
  	f, present := styp.FieldByName("d")
  	if !present {
  		t.Errorf("FieldByName says present field is absent")
  	}
  	testType(t, 6, f.Type, "float32")
  
  	f, present = styp.FieldByName("absent")
  	if present {
  		t.Errorf("FieldByName says absent field is present")
  	}
  
  	typ = TypeOf([32]int32{})
  	testType(t, 7, typ, "[32]int32")
  	testType(t, 8, typ.Elem(), "int32")
  
  	typ = TypeOf((map[string]*int32)(nil))
  	testType(t, 9, typ, "map[string]*int32")
  	mtyp := typ
  	testType(t, 10, mtyp.Key(), "string")
  	testType(t, 11, mtyp.Elem(), "*int32")
  
  	typ = TypeOf((chan<- string)(nil))
  	testType(t, 12, typ, "chan<- string")
  	testType(t, 13, typ.Elem(), "string")
  
  	// make sure tag strings are not part of element type
  	typ = TypeOf(struct {
  		d []uint32 `reflect:"TAG"`
  	}{}).Field(0).Type
  	testType(t, 14, typ, "[]uint32")
  }
  
  func TestInterfaceGet(t *testing.T) {
  	var inter struct {
  		E interface{}
  	}
  	inter.E = 123.456
  	v1 := ValueOf(&inter)
  	v2 := v1.Elem().Field(0)
  	assert(t, v2.Type().String(), "interface {}")
  	i2 := v2.Interface()
  	v3 := ValueOf(i2)
  	assert(t, v3.Type().String(), "float64")
  }
  
  func TestInterfaceValue(t *testing.T) {
  	var inter struct {
  		E interface{}
  	}
  	inter.E = 123.456
  	v1 := ValueOf(&inter)
  	v2 := v1.Elem().Field(0)
  	assert(t, v2.Type().String(), "interface {}")
  	v3 := v2.Elem()
  	assert(t, v3.Type().String(), "float64")
  
  	i3 := v2.Interface()
  	if _, ok := i3.(float64); !ok {
  		t.Error("v2.Interface() did not return float64, got ", TypeOf(i3))
  	}
  }
  
  func TestFunctionValue(t *testing.T) {
  	var x interface{} = func() {}
  	v := ValueOf(x)
  	if fmt.Sprint(v.Interface()) != fmt.Sprint(x) {
  		t.Fatalf("TestFunction returned wrong pointer")
  	}
  	assert(t, v.Type().String(), "func()")
  }
  
  var appendTests = []struct {
  	orig, extra []int
  }{
  	{make([]int, 2, 4), []int{22}},
  	{make([]int, 2, 4), []int{22, 33, 44}},
  }
  
  func sameInts(x, y []int) bool {
  	if len(x) != len(y) {
  		return false
  	}
  	for i, xx := range x {
  		if xx != y[i] {
  			return false
  		}
  	}
  	return true
  }
  
  func TestAppend(t *testing.T) {
  	for i, test := range appendTests {
  		origLen, extraLen := len(test.orig), len(test.extra)
  		want := append(test.orig, test.extra...)
  		// Convert extra from []int to []Value.
  		e0 := make([]Value, len(test.extra))
  		for j, e := range test.extra {
  			e0[j] = ValueOf(e)
  		}
  		// Convert extra from []int to *SliceValue.
  		e1 := ValueOf(test.extra)
  		// Test Append.
  		a0 := ValueOf(test.orig)
  		have0 := Append(a0, e0...).Interface().([]int)
  		if !sameInts(have0, want) {
  			t.Errorf("Append #%d: have %v, want %v (%p %p)", i, have0, want, test.orig, have0)
  		}
  		// Check that the orig and extra slices were not modified.
  		if len(test.orig) != origLen {
  			t.Errorf("Append #%d origLen: have %v, want %v", i, len(test.orig), origLen)
  		}
  		if len(test.extra) != extraLen {
  			t.Errorf("Append #%d extraLen: have %v, want %v", i, len(test.extra), extraLen)
  		}
  		// Test AppendSlice.
  		a1 := ValueOf(test.orig)
  		have1 := AppendSlice(a1, e1).Interface().([]int)
  		if !sameInts(have1, want) {
  			t.Errorf("AppendSlice #%d: have %v, want %v", i, have1, want)
  		}
  		// Check that the orig and extra slices were not modified.
  		if len(test.orig) != origLen {
  			t.Errorf("AppendSlice #%d origLen: have %v, want %v", i, len(test.orig), origLen)
  		}
  		if len(test.extra) != extraLen {
  			t.Errorf("AppendSlice #%d extraLen: have %v, want %v", i, len(test.extra), extraLen)
  		}
  	}
  }
  
  func TestCopy(t *testing.T) {
  	a := []int{1, 2, 3, 4, 10, 9, 8, 7}
  	b := []int{11, 22, 33, 44, 1010, 99, 88, 77, 66, 55, 44}
  	c := []int{11, 22, 33, 44, 1010, 99, 88, 77, 66, 55, 44}
  	for i := 0; i < len(b); i++ {
  		if b[i] != c[i] {
  			t.Fatalf("b != c before test")
  		}
  	}
  	a1 := a
  	b1 := b
  	aa := ValueOf(&a1).Elem()
  	ab := ValueOf(&b1).Elem()
  	for tocopy := 1; tocopy <= 7; tocopy++ {
  		aa.SetLen(tocopy)
  		Copy(ab, aa)
  		aa.SetLen(8)
  		for i := 0; i < tocopy; i++ {
  			if a[i] != b[i] {
  				t.Errorf("(i) tocopy=%d a[%d]=%d, b[%d]=%d",
  					tocopy, i, a[i], i, b[i])
  			}
  		}
  		for i := tocopy; i < len(b); i++ {
  			if b[i] != c[i] {
  				if i < len(a) {
  					t.Errorf("(ii) tocopy=%d a[%d]=%d, b[%d]=%d, c[%d]=%d",
  						tocopy, i, a[i], i, b[i], i, c[i])
  				} else {
  					t.Errorf("(iii) tocopy=%d b[%d]=%d, c[%d]=%d",
  						tocopy, i, b[i], i, c[i])
  				}
  			} else {
  				t.Logf("tocopy=%d elem %d is okay\n", tocopy, i)
  			}
  		}
  	}
  }
  
  func TestCopyArray(t *testing.T) {
  	a := [8]int{1, 2, 3, 4, 10, 9, 8, 7}
  	b := [11]int{11, 22, 33, 44, 1010, 99, 88, 77, 66, 55, 44}
  	c := b
  	aa := ValueOf(&a).Elem()
  	ab := ValueOf(&b).Elem()
  	Copy(ab, aa)
  	for i := 0; i < len(a); i++ {
  		if a[i] != b[i] {
  			t.Errorf("(i) a[%d]=%d, b[%d]=%d", i, a[i], i, b[i])
  		}
  	}
  	for i := len(a); i < len(b); i++ {
  		if b[i] != c[i] {
  			t.Errorf("(ii) b[%d]=%d, c[%d]=%d", i, b[i], i, c[i])
  		} else {
  			t.Logf("elem %d is okay\n", i)
  		}
  	}
  }
  
  func TestBigUnnamedStruct(t *testing.T) {
  	b := struct{ a, b, c, d int64 }{1, 2, 3, 4}
  	v := ValueOf(b)
  	b1 := v.Interface().(struct {
  		a, b, c, d int64
  	})
  	if b1.a != b.a || b1.b != b.b || b1.c != b.c || b1.d != b.d {
  		t.Errorf("ValueOf(%v).Interface().(*Big) = %v", b, b1)
  	}
  }
  
  type big struct {
  	a, b, c, d, e int64
  }
  
  func TestBigStruct(t *testing.T) {
  	b := big{1, 2, 3, 4, 5}
  	v := ValueOf(b)
  	b1 := v.Interface().(big)
  	if b1.a != b.a || b1.b != b.b || b1.c != b.c || b1.d != b.d || b1.e != b.e {
  		t.Errorf("ValueOf(%v).Interface().(big) = %v", b, b1)
  	}
  }
  
  type Basic struct {
  	x int
  	y float32
  }
  
  type NotBasic Basic
  
  type DeepEqualTest struct {
  	a, b interface{}
  	eq   bool
  }
  
  // Simple functions for DeepEqual tests.
  var (
  	fn1 func()             // nil.
  	fn2 func()             // nil.
  	fn3 = func() { fn1() } // Not nil.
  )
  
  type self struct{}
  
  type Loop *Loop
  type Loopy interface{}
  
  var loop1, loop2 Loop
  var loopy1, loopy2 Loopy
  
  func init() {
  	loop1 = &loop2
  	loop2 = &loop1
  
  	loopy1 = &loopy2
  	loopy2 = &loopy1
  }
  
  var deepEqualTests = []DeepEqualTest{
  	// Equalities
  	{nil, nil, true},
  	{1, 1, true},
  	{int32(1), int32(1), true},
  	{0.5, 0.5, true},
  	{float32(0.5), float32(0.5), true},
  	{"hello", "hello", true},
  	{make([]int, 10), make([]int, 10), true},
  	{&[3]int{1, 2, 3}, &[3]int{1, 2, 3}, true},
  	{Basic{1, 0.5}, Basic{1, 0.5}, true},
  	{error(nil), error(nil), true},
  	{map[int]string{1: "one", 2: "two"}, map[int]string{2: "two", 1: "one"}, true},
  	{fn1, fn2, true},
  
  	// Inequalities
  	{1, 2, false},
  	{int32(1), int32(2), false},
  	{0.5, 0.6, false},
  	{float32(0.5), float32(0.6), false},
  	{"hello", "hey", false},
  	{make([]int, 10), make([]int, 11), false},
  	{&[3]int{1, 2, 3}, &[3]int{1, 2, 4}, false},
  	{Basic{1, 0.5}, Basic{1, 0.6}, false},
  	{Basic{1, 0}, Basic{2, 0}, false},
  	{map[int]string{1: "one", 3: "two"}, map[int]string{2: "two", 1: "one"}, false},
  	{map[int]string{1: "one", 2: "txo"}, map[int]string{2: "two", 1: "one"}, false},
  	{map[int]string{1: "one"}, map[int]string{2: "two", 1: "one"}, false},
  	{map[int]string{2: "two", 1: "one"}, map[int]string{1: "one"}, false},
  	{nil, 1, false},
  	{1, nil, false},
  	{fn1, fn3, false},
  	{fn3, fn3, false},
  	{[][]int{{1}}, [][]int{{2}}, false},
  	{math.NaN(), math.NaN(), false},
  	{&[1]float64{math.NaN()}, &[1]float64{math.NaN()}, false},
  	{&[1]float64{math.NaN()}, self{}, true},
  	{[]float64{math.NaN()}, []float64{math.NaN()}, false},
  	{[]float64{math.NaN()}, self{}, true},
  	{map[float64]float64{math.NaN(): 1}, map[float64]float64{1: 2}, false},
  	{map[float64]float64{math.NaN(): 1}, self{}, true},
  
  	// Nil vs empty: not the same.
  	{[]int{}, []int(nil), false},
  	{[]int{}, []int{}, true},
  	{[]int(nil), []int(nil), true},
  	{map[int]int{}, map[int]int(nil), false},
  	{map[int]int{}, map[int]int{}, true},
  	{map[int]int(nil), map[int]int(nil), true},
  
  	// Mismatched types
  	{1, 1.0, false},
  	{int32(1), int64(1), false},
  	{0.5, "hello", false},
  	{[]int{1, 2, 3}, [3]int{1, 2, 3}, false},
  	{&[3]interface{}{1, 2, 4}, &[3]interface{}{1, 2, "s"}, false},
  	{Basic{1, 0.5}, NotBasic{1, 0.5}, false},
  	{map[uint]string{1: "one", 2: "two"}, map[int]string{2: "two", 1: "one"}, false},
  
  	// Possible loops.
  	{&loop1, &loop1, true},
  	{&loop1, &loop2, true},
  	{&loopy1, &loopy1, true},
  	{&loopy1, &loopy2, true},
  }
  
  func TestDeepEqual(t *testing.T) {
  	for _, test := range deepEqualTests {
  		if test.b == (self{}) {
  			test.b = test.a
  		}
  		if r := DeepEqual(test.a, test.b); r != test.eq {
  			t.Errorf("DeepEqual(%v, %v) = %v, want %v", test.a, test.b, r, test.eq)
  		}
  	}
  }
  
  func TestTypeOf(t *testing.T) {
  	// Special case for nil
  	if typ := TypeOf(nil); typ != nil {
  		t.Errorf("expected nil type for nil value; got %v", typ)
  	}
  	for _, test := range deepEqualTests {
  		v := ValueOf(test.a)
  		if !v.IsValid() {
  			continue
  		}
  		typ := TypeOf(test.a)
  		if typ != v.Type() {
  			t.Errorf("TypeOf(%v) = %v, but ValueOf(%v).Type() = %v", test.a, typ, test.a, v.Type())
  		}
  	}
  }
  
  type Recursive struct {
  	x int
  	r *Recursive
  }
  
  func TestDeepEqualRecursiveStruct(t *testing.T) {
  	a, b := new(Recursive), new(Recursive)
  	*a = Recursive{12, a}
  	*b = Recursive{12, b}
  	if !DeepEqual(a, b) {
  		t.Error("DeepEqual(recursive same) = false, want true")
  	}
  }
  
  type _Complex struct {
  	a int
  	b [3]*_Complex
  	c *string
  	d map[float64]float64
  }
  
  func TestDeepEqualComplexStruct(t *testing.T) {
  	m := make(map[float64]float64)
  	stra, strb := "hello", "hello"
  	a, b := new(_Complex), new(_Complex)
  	*a = _Complex{5, [3]*_Complex{a, b, a}, &stra, m}
  	*b = _Complex{5, [3]*_Complex{b, a, a}, &strb, m}
  	if !DeepEqual(a, b) {
  		t.Error("DeepEqual(complex same) = false, want true")
  	}
  }
  
  func TestDeepEqualComplexStructInequality(t *testing.T) {
  	m := make(map[float64]float64)
  	stra, strb := "hello", "helloo" // Difference is here
  	a, b := new(_Complex), new(_Complex)
  	*a = _Complex{5, [3]*_Complex{a, b, a}, &stra, m}
  	*b = _Complex{5, [3]*_Complex{b, a, a}, &strb, m}
  	if DeepEqual(a, b) {
  		t.Error("DeepEqual(complex different) = true, want false")
  	}
  }
  
  type UnexpT struct {
  	m map[int]int
  }
  
  func TestDeepEqualUnexportedMap(t *testing.T) {
  	// Check that DeepEqual can look at unexported fields.
  	x1 := UnexpT{map[int]int{1: 2}}
  	x2 := UnexpT{map[int]int{1: 2}}
  	if !DeepEqual(&x1, &x2) {
  		t.Error("DeepEqual(x1, x2) = false, want true")
  	}
  
  	y1 := UnexpT{map[int]int{2: 3}}
  	if DeepEqual(&x1, &y1) {
  		t.Error("DeepEqual(x1, y1) = true, want false")
  	}
  }
  
  func check2ndField(x interface{}, offs uintptr, t *testing.T) {
  	s := ValueOf(x)
  	f := s.Type().Field(1)
  	if f.Offset != offs {
  		t.Error("mismatched offsets in structure alignment:", f.Offset, offs)
  	}
  }
  
  // Check that structure alignment & offsets viewed through reflect agree with those
  // from the compiler itself.
  func TestAlignment(t *testing.T) {
  	type T1inner struct {
  		a int
  	}
  	type T1 struct {
  		T1inner
  		f int
  	}
  	type T2inner struct {
  		a, b int
  	}
  	type T2 struct {
  		T2inner
  		f int
  	}
  
  	x := T1{T1inner{2}, 17}
  	check2ndField(x, uintptr(unsafe.Pointer(&x.f))-uintptr(unsafe.Pointer(&x)), t)
  
  	x1 := T2{T2inner{2, 3}, 17}
  	check2ndField(x1, uintptr(unsafe.Pointer(&x1.f))-uintptr(unsafe.Pointer(&x1)), t)
  }
  
  func Nil(a interface{}, t *testing.T) {
  	n := ValueOf(a).Field(0)
  	if !n.IsNil() {
  		t.Errorf("%v should be nil", a)
  	}
  }
  
  func NotNil(a interface{}, t *testing.T) {
  	n := ValueOf(a).Field(0)
  	if n.IsNil() {
  		t.Errorf("value of type %v should not be nil", ValueOf(a).Type().String())
  	}
  }
  
  func TestIsNil(t *testing.T) {
  	// These implement IsNil.
  	// Wrap in extra struct to hide interface type.
  	doNil := []interface{}{
  		struct{ x *int }{},
  		struct{ x interface{} }{},
  		struct{ x map[string]int }{},
  		struct{ x func() bool }{},
  		struct{ x chan int }{},
  		struct{ x []string }{},
  	}
  	for _, ts := range doNil {
  		ty := TypeOf(ts).Field(0).Type
  		v := Zero(ty)
  		v.IsNil() // panics if not okay to call
  	}
  
  	// Check the implementations
  	var pi struct {
  		x *int
  	}
  	Nil(pi, t)
  	pi.x = new(int)
  	NotNil(pi, t)
  
  	var si struct {
  		x []int
  	}
  	Nil(si, t)
  	si.x = make([]int, 10)
  	NotNil(si, t)
  
  	var ci struct {
  		x chan int
  	}
  	Nil(ci, t)
  	ci.x = make(chan int)
  	NotNil(ci, t)
  
  	var mi struct {
  		x map[int]int
  	}
  	Nil(mi, t)
  	mi.x = make(map[int]int)
  	NotNil(mi, t)
  
  	var ii struct {
  		x interface{}
  	}
  	Nil(ii, t)
  	ii.x = 2
  	NotNil(ii, t)
  
  	var fi struct {
  		x func(t *testing.T)
  	}
  	Nil(fi, t)
  	fi.x = TestIsNil
  	NotNil(fi, t)
  }
  
  func TestInterfaceExtraction(t *testing.T) {
  	var s struct {
  		W io.Writer
  	}
  
  	s.W = os.Stdout
  	v := Indirect(ValueOf(&s)).Field(0).Interface()
  	if v != s.W.(interface{}) {
  		t.Error("Interface() on interface: ", v, s.W)
  	}
  }
  
  func TestNilPtrValueSub(t *testing.T) {
  	var pi *int
  	if pv := ValueOf(pi); pv.Elem().IsValid() {
  		t.Error("ValueOf((*int)(nil)).Elem().IsValid()")
  	}
  }
  
  func TestMap(t *testing.T) {
  	m := map[string]int{"a": 1, "b": 2}
  	mv := ValueOf(m)
  	if n := mv.Len(); n != len(m) {
  		t.Errorf("Len = %d, want %d", n, len(m))
  	}
  	keys := mv.MapKeys()
  	newmap := MakeMap(mv.Type())
  	for k, v := range m {
  		// Check that returned Keys match keys in range.
  		// These aren't required to be in the same order.
  		seen := false
  		for _, kv := range keys {
  			if kv.String() == k {
  				seen = true
  				break
  			}
  		}
  		if !seen {
  			t.Errorf("Missing key %q", k)
  		}
  
  		// Check that value lookup is correct.
  		vv := mv.MapIndex(ValueOf(k))
  		if vi := vv.Int(); vi != int64(v) {
  			t.Errorf("Key %q: have value %d, want %d", k, vi, v)
  		}
  
  		// Copy into new map.
  		newmap.SetMapIndex(ValueOf(k), ValueOf(v))
  	}
  	vv := mv.MapIndex(ValueOf("not-present"))
  	if vv.IsValid() {
  		t.Errorf("Invalid key: got non-nil value %s", valueToString(vv))
  	}
  
  	newm := newmap.Interface().(map[string]int)
  	if len(newm) != len(m) {
  		t.Errorf("length after copy: newm=%d, m=%d", len(newm), len(m))
  	}
  
  	for k, v := range newm {
  		mv, ok := m[k]
  		if mv != v {
  			t.Errorf("newm[%q] = %d, but m[%q] = %d, %v", k, v, k, mv, ok)
  		}
  	}
  
  	newmap.SetMapIndex(ValueOf("a"), Value{})
  	v, ok := newm["a"]
  	if ok {
  		t.Errorf("newm[\"a\"] = %d after delete", v)
  	}
  
  	mv = ValueOf(&m).Elem()
  	mv.Set(Zero(mv.Type()))
  	if m != nil {
  		t.Errorf("mv.Set(nil) failed")
  	}
  }
  
  func TestNilMap(t *testing.T) {
  	var m map[string]int
  	mv := ValueOf(m)
  	keys := mv.MapKeys()
  	if len(keys) != 0 {
  		t.Errorf(">0 keys for nil map: %v", keys)
  	}
  
  	// Check that value for missing key is zero.
  	x := mv.MapIndex(ValueOf("hello"))
  	if x.Kind() != Invalid {
  		t.Errorf("m.MapIndex(\"hello\") for nil map = %v, want Invalid Value", x)
  	}
  
  	// Check big value too.
  	var mbig map[string][10 << 20]byte
  	x = ValueOf(mbig).MapIndex(ValueOf("hello"))
  	if x.Kind() != Invalid {
  		t.Errorf("mbig.MapIndex(\"hello\") for nil map = %v, want Invalid Value", x)
  	}
  
  	// Test that deletes from a nil map succeed.
  	mv.SetMapIndex(ValueOf("hi"), Value{})
  }
  
  func TestChan(t *testing.T) {
  	for loop := 0; loop < 2; loop++ {
  		var c chan int
  		var cv Value
  
  		// check both ways to allocate channels
  		switch loop {
  		case 1:
  			c = make(chan int, 1)
  			cv = ValueOf(c)
  		case 0:
  			cv = MakeChan(TypeOf(c), 1)
  			c = cv.Interface().(chan int)
  		}
  
  		// Send
  		cv.Send(ValueOf(2))
  		if i := <-c; i != 2 {
  			t.Errorf("reflect Send 2, native recv %d", i)
  		}
  
  		// Recv
  		c <- 3
  		if i, ok := cv.Recv(); i.Int() != 3 || !ok {
  			t.Errorf("native send 3, reflect Recv %d, %t", i.Int(), ok)
  		}
  
  		// TryRecv fail
  		val, ok := cv.TryRecv()
  		if val.IsValid() || ok {
  			t.Errorf("TryRecv on empty chan: %s, %t", valueToString(val), ok)
  		}
  
  		// TryRecv success
  		c <- 4
  		val, ok = cv.TryRecv()
  		if !val.IsValid() {
  			t.Errorf("TryRecv on ready chan got nil")
  		} else if i := val.Int(); i != 4 || !ok {
  			t.Errorf("native send 4, TryRecv %d, %t", i, ok)
  		}
  
  		// TrySend fail
  		c <- 100
  		ok = cv.TrySend(ValueOf(5))
  		i := <-c
  		if ok {
  			t.Errorf("TrySend on full chan succeeded: value %d", i)
  		}
  
  		// TrySend success
  		ok = cv.TrySend(ValueOf(6))
  		if !ok {
  			t.Errorf("TrySend on empty chan failed")
  			select {
  			case x := <-c:
  				t.Errorf("TrySend failed but it did send %d", x)
  			default:
  			}
  		} else {
  			if i = <-c; i != 6 {
  				t.Errorf("TrySend 6, recv %d", i)
  			}
  		}
  
  		// Close
  		c <- 123
  		cv.Close()
  		if i, ok := cv.Recv(); i.Int() != 123 || !ok {
  			t.Errorf("send 123 then close; Recv %d, %t", i.Int(), ok)
  		}
  		if i, ok := cv.Recv(); i.Int() != 0 || ok {
  			t.Errorf("after close Recv %d, %t", i.Int(), ok)
  		}
  	}
  
  	// check creation of unbuffered channel
  	var c chan int
  	cv := MakeChan(TypeOf(c), 0)
  	c = cv.Interface().(chan int)
  	if cv.TrySend(ValueOf(7)) {
  		t.Errorf("TrySend on sync chan succeeded")
  	}
  	if v, ok := cv.TryRecv(); v.IsValid() || ok {
  		t.Errorf("TryRecv on sync chan succeeded: isvalid=%v ok=%v", v.IsValid(), ok)
  	}
  
  	// len/cap
  	cv = MakeChan(TypeOf(c), 10)
  	c = cv.Interface().(chan int)
  	for i := 0; i < 3; i++ {
  		c <- i
  	}
  	if l, m := cv.Len(), cv.Cap(); l != len(c) || m != cap(c) {
  		t.Errorf("Len/Cap = %d/%d want %d/%d", l, m, len(c), cap(c))
  	}
  }
  
  // caseInfo describes a single case in a select test.
  type caseInfo struct {
  	desc      string
  	canSelect bool
  	recv      Value
  	closed    bool
  	helper    func()
  	panic     bool
  }
  
  var allselect = flag.Bool("allselect", false, "exhaustive select test")
  
  func TestSelect(t *testing.T) {
  	selectWatch.once.Do(func() { go selectWatcher() })
  
  	var x exhaustive
  	nch := 0
  	newop := func(n int, cap int) (ch, val Value) {
  		nch++
  		if nch%101%2 == 1 {
  			c := make(chan int, cap)
  			ch = ValueOf(c)
  			val = ValueOf(n)
  		} else {
  			c := make(chan string, cap)
  			ch = ValueOf(c)
  			val = ValueOf(fmt.Sprint(n))
  		}
  		return
  	}
  
  	for n := 0; x.Next(); n++ {
  		if testing.Short() && n >= 1000 {
  			break
  		}
  		if n >= 100000 && !*allselect {
  			break
  		}
  		if n%100000 == 0 && testing.Verbose() {
  			println("TestSelect", n)
  		}
  		var cases []SelectCase
  		var info []caseInfo
  
  		// Ready send.
  		if x.Maybe() {
  			ch, val := newop(len(cases), 1)
  			cases = append(cases, SelectCase{
  				Dir:  SelectSend,
  				Chan: ch,
  				Send: val,
  			})
  			info = append(info, caseInfo{desc: "ready send", canSelect: true})
  		}
  
  		// Ready recv.
  		if x.Maybe() {
  			ch, val := newop(len(cases), 1)
  			ch.Send(val)
  			cases = append(cases, SelectCase{
  				Dir:  SelectRecv,
  				Chan: ch,
  			})
  			info = append(info, caseInfo{desc: "ready recv", canSelect: true, recv: val})
  		}
  
  		// Blocking send.
  		if x.Maybe() {
  			ch, val := newop(len(cases), 0)
  			cases = append(cases, SelectCase{
  				Dir:  SelectSend,
  				Chan: ch,
  				Send: val,
  			})
  			// Let it execute?
  			if x.Maybe() {
  				f := func() { ch.Recv() }
  				info = append(info, caseInfo{desc: "blocking send", helper: f})
  			} else {
  				info = append(info, caseInfo{desc: "blocking send"})
  			}
  		}
  
  		// Blocking recv.
  		if x.Maybe() {
  			ch, val := newop(len(cases), 0)
  			cases = append(cases, SelectCase{
  				Dir:  SelectRecv,
  				Chan: ch,
  			})
  			// Let it execute?
  			if x.Maybe() {
  				f := func() { ch.Send(val) }
  				info = append(info, caseInfo{desc: "blocking recv", recv: val, helper: f})
  			} else {
  				info = append(info, caseInfo{desc: "blocking recv"})
  			}
  		}
  
  		// Zero Chan send.
  		if x.Maybe() {
  			// Maybe include value to send.
  			var val Value
  			if x.Maybe() {
  				val = ValueOf(100)
  			}
  			cases = append(cases, SelectCase{
  				Dir:  SelectSend,
  				Send: val,
  			})
  			info = append(info, caseInfo{desc: "zero Chan send"})
  		}
  
  		// Zero Chan receive.
  		if x.Maybe() {
  			cases = append(cases, SelectCase{
  				Dir: SelectRecv,
  			})
  			info = append(info, caseInfo{desc: "zero Chan recv"})
  		}
  
  		// nil Chan send.
  		if x.Maybe() {
  			cases = append(cases, SelectCase{
  				Dir:  SelectSend,
  				Chan: ValueOf((chan int)(nil)),
  				Send: ValueOf(101),
  			})
  			info = append(info, caseInfo{desc: "nil Chan send"})
  		}
  
  		// nil Chan recv.
  		if x.Maybe() {
  			cases = append(cases, SelectCase{
  				Dir:  SelectRecv,
  				Chan: ValueOf((chan int)(nil)),
  			})
  			info = append(info, caseInfo{desc: "nil Chan recv"})
  		}
  
  		// closed Chan send.
  		if x.Maybe() {
  			ch := make(chan int)
  			close(ch)
  			cases = append(cases, SelectCase{
  				Dir:  SelectSend,
  				Chan: ValueOf(ch),
  				Send: ValueOf(101),
  			})
  			info = append(info, caseInfo{desc: "closed Chan send", canSelect: true, panic: true})
  		}
  
  		// closed Chan recv.
  		if x.Maybe() {
  			ch, val := newop(len(cases), 0)
  			ch.Close()
  			val = Zero(val.Type())
  			cases = append(cases, SelectCase{
  				Dir:  SelectRecv,
  				Chan: ch,
  			})
  			info = append(info, caseInfo{desc: "closed Chan recv", canSelect: true, closed: true, recv: val})
  		}
  
  		var helper func() // goroutine to help the select complete
  
  		// Add default? Must be last case here, but will permute.
  		// Add the default if the select would otherwise
  		// block forever, and maybe add it anyway.
  		numCanSelect := 0
  		canProceed := false
  		canBlock := true
  		canPanic := false
  		helpers := []int{}
  		for i, c := range info {
  			if c.canSelect {
  				canProceed = true
  				canBlock = false
  				numCanSelect++
  				if c.panic {
  					canPanic = true
  				}
  			} else if c.helper != nil {
  				canProceed = true
  				helpers = append(helpers, i)
  			}
  		}
  		if !canProceed || x.Maybe() {
  			cases = append(cases, SelectCase{
  				Dir: SelectDefault,
  			})
  			info = append(info, caseInfo{desc: "default", canSelect: canBlock})
  			numCanSelect++
  		} else if canBlock {
  			// Select needs to communicate with another goroutine.
  			cas := &info[helpers[x.Choose(len(helpers))]]
  			helper = cas.helper
  			cas.canSelect = true
  			numCanSelect++
  		}
  
  		// Permute cases and case info.
  		// Doing too much here makes the exhaustive loop
  		// too exhausting, so just do two swaps.
  		for loop := 0; loop < 2; loop++ {
  			i := x.Choose(len(cases))
  			j := x.Choose(len(cases))
  			cases[i], cases[j] = cases[j], cases[i]
  			info[i], info[j] = info[j], info[i]
  		}
  
  		if helper != nil {
  			// We wait before kicking off a goroutine to satisfy a blocked select.
  			// The pause needs to be big enough to let the select block before
  			// we run the helper, but if we lose that race once in a while it's okay: the
  			// select will just proceed immediately. Not a big deal.
  			// For short tests we can grow [sic] the timeout a bit without fear of taking too long
  			pause := 10 * time.Microsecond
  			if testing.Short() {
  				pause = 100 * time.Microsecond
  			}
  			time.AfterFunc(pause, helper)
  		}
  
  		// Run select.
  		i, recv, recvOK, panicErr := runSelect(cases, info)
  		if panicErr != nil && !canPanic {
  			t.Fatalf("%s\npanicked unexpectedly: %v", fmtSelect(info), panicErr)
  		}
  		if panicErr == nil && canPanic && numCanSelect == 1 {
  			t.Fatalf("%s\nselected #%d incorrectly (should panic)", fmtSelect(info), i)
  		}
  		if panicErr != nil {
  			continue
  		}
  
  		cas := info[i]
  		if !cas.canSelect {
  			recvStr := ""
  			if recv.IsValid() {
  				recvStr = fmt.Sprintf(", received %v, %v", recv.Interface(), recvOK)
  			}
  			t.Fatalf("%s\nselected #%d incorrectly%s", fmtSelect(info), i, recvStr)
  			continue
  		}
  		if cas.panic {
  			t.Fatalf("%s\nselected #%d incorrectly (case should panic)", fmtSelect(info), i)
  			continue
  		}
  
  		if cases[i].Dir == SelectRecv {
  			if !recv.IsValid() {
  				t.Fatalf("%s\nselected #%d but got %v, %v, want %v, %v", fmtSelect(info), i, recv, recvOK, cas.recv.Interface(), !cas.closed)
  			}
  			if !cas.recv.IsValid() {
  				t.Fatalf("%s\nselected #%d but internal error: missing recv value", fmtSelect(info), i)
  			}
  			if recv.Interface() != cas.recv.Interface() || recvOK != !cas.closed {
  				if recv.Interface() == cas.recv.Interface() && recvOK == !cas.closed {
  					t.Fatalf("%s\nselected #%d, got %#v, %v, and DeepEqual is broken on %T", fmtSelect(info), i, recv.Interface(), recvOK, recv.Interface())
  				}
  				t.Fatalf("%s\nselected #%d but got %#v, %v, want %#v, %v", fmtSelect(info), i, recv.Interface(), recvOK, cas.recv.Interface(), !cas.closed)
  			}
  		} else {
  			if recv.IsValid() || recvOK {
  				t.Fatalf("%s\nselected #%d but got %v, %v, want %v, %v", fmtSelect(info), i, recv, recvOK, Value{}, false)
  			}
  		}
  	}
  }
  
  // selectWatch and the selectWatcher are a watchdog mechanism for running Select.
  // If the selectWatcher notices that the select has been blocked for >1 second, it prints
  // an error describing the select and panics the entire test binary.
  var selectWatch struct {
  	sync.Mutex
  	once sync.Once
  	now  time.Time
  	info []caseInfo
  }
  
  func selectWatcher() {
  	for {
  		time.Sleep(1 * time.Second)
  		selectWatch.Lock()
  		if selectWatch.info != nil && time.Since(selectWatch.now) > 10*time.Second {
  			fmt.Fprintf(os.Stderr, "TestSelect:\n%s blocked indefinitely\n", fmtSelect(selectWatch.info))
  			panic("select stuck")
  		}
  		selectWatch.Unlock()
  	}
  }
  
  // runSelect runs a single select test.
  // It returns the values returned by Select but also returns
  // a panic value if the Select panics.
  func runSelect(cases []SelectCase, info []caseInfo) (chosen int, recv Value, recvOK bool, panicErr interface{}) {
  	defer func() {
  		panicErr = recover()
  
  		selectWatch.Lock()
  		selectWatch.info = nil
  		selectWatch.Unlock()
  	}()
  
  	selectWatch.Lock()
  	selectWatch.now = time.Now()
  	selectWatch.info = info
  	selectWatch.Unlock()
  
  	chosen, recv, recvOK = Select(cases)
  	return
  }
  
  // fmtSelect formats the information about a single select test.
  func fmtSelect(info []caseInfo) string {
  	var buf bytes.Buffer
  	fmt.Fprintf(&buf, "\nselect {\n")
  	for i, cas := range info {
  		fmt.Fprintf(&buf, "%d: %s", i, cas.desc)
  		if cas.recv.IsValid() {
  			fmt.Fprintf(&buf, " val=%#v", cas.recv.Interface())
  		}
  		if cas.canSelect {
  			fmt.Fprintf(&buf, " canselect")
  		}
  		if cas.panic {
  			fmt.Fprintf(&buf, " panic")
  		}
  		fmt.Fprintf(&buf, "\n")
  	}
  	fmt.Fprintf(&buf, "}")
  	return buf.String()
  }
  
  type two [2]uintptr
  
  // Difficult test for function call because of
  // implicit padding between arguments.
  func dummy(b byte, c int, d byte, e two, f byte, g float32, h byte) (i byte, j int, k byte, l two, m byte, n float32, o byte) {
  	return b, c, d, e, f, g, h
  }
  
  func TestFunc(t *testing.T) {
  	ret := ValueOf(dummy).Call([]Value{
  		ValueOf(byte(10)),
  		ValueOf(20),
  		ValueOf(byte(30)),
  		ValueOf(two{40, 50}),
  		ValueOf(byte(60)),
  		ValueOf(float32(70)),
  		ValueOf(byte(80)),
  	})
  	if len(ret) != 7 {
  		t.Fatalf("Call returned %d values, want 7", len(ret))
  	}
  
  	i := byte(ret[0].Uint())
  	j := int(ret[1].Int())
  	k := byte(ret[2].Uint())
  	l := ret[3].Interface().(two)
  	m := byte(ret[4].Uint())
  	n := float32(ret[5].Float())
  	o := byte(ret[6].Uint())
  
  	if i != 10 || j != 20 || k != 30 || l != (two{40, 50}) || m != 60 || n != 70 || o != 80 {
  		t.Errorf("Call returned %d, %d, %d, %v, %d, %g, %d; want 10, 20, 30, [40, 50], 60, 70, 80", i, j, k, l, m, n, o)
  	}
  
  	for i, v := range ret {
  		if v.CanAddr() {
  			t.Errorf("result %d is addressable", i)
  		}
  	}
  }
  
  type emptyStruct struct{}
  
  type nonEmptyStruct struct {
  	member int
  }
  
  func returnEmpty() emptyStruct {
  	return emptyStruct{}
  }
  
  func takesEmpty(e emptyStruct) {
  }
  
  func returnNonEmpty(i int) nonEmptyStruct {
  	return nonEmptyStruct{member: i}
  }
  
  func takesNonEmpty(n nonEmptyStruct) int {
  	return n.member
  }
  
  func TestCallWithStruct(t *testing.T) {
  	r := ValueOf(returnEmpty).Call(nil)
  	if len(r) != 1 || r[0].Type() != TypeOf(emptyStruct{}) {
  		t.Errorf("returning empty struct returned %#v instead", r)
  	}
  	r = ValueOf(takesEmpty).Call([]Value{ValueOf(emptyStruct{})})
  	if len(r) != 0 {
  		t.Errorf("takesEmpty returned values: %#v", r)
  	}
  	r = ValueOf(returnNonEmpty).Call([]Value{ValueOf(42)})
  	if len(r) != 1 || r[0].Type() != TypeOf(nonEmptyStruct{}) || r[0].Field(0).Int() != 42 {
  		t.Errorf("returnNonEmpty returned %#v", r)
  	}
  	r = ValueOf(takesNonEmpty).Call([]Value{ValueOf(nonEmptyStruct{member: 42})})
  	if len(r) != 1 || r[0].Type() != TypeOf(1) || r[0].Int() != 42 {
  		t.Errorf("takesNonEmpty returned %#v", r)
  	}
  }
  
  func TestCallReturnsEmpty(t *testing.T) {
  	// Issue 21717: past-the-end pointer write in Call with
  	// nonzero-sized frame and zero-sized return value.
  	runtime.GC()
  	var finalized uint32
  	f := func() (emptyStruct, *int) {
  		i := new(int)
  		runtime.SetFinalizer(i, func(*int) { atomic.StoreUint32(&finalized, 1) })
  		return emptyStruct{}, i
  	}
  	v := ValueOf(f).Call(nil)[0] // out[0] should not alias out[1]'s memory, so the finalizer should run.
  	timeout := time.After(5 * time.Second)
  	for atomic.LoadUint32(&finalized) == 0 {
  		select {
  		case <-timeout:
  			t.Fatal("finalizer did not run")
  		default:
  		}
  		runtime.Gosched()
  		runtime.GC()
  	}
  	runtime.KeepAlive(v)
  }
  
  func BenchmarkCall(b *testing.B) {
  	fv := ValueOf(func(a, b string) {})
  	b.ReportAllocs()
  	b.RunParallel(func(pb *testing.PB) {
  		args := []Value{ValueOf("a"), ValueOf("b")}
  		for pb.Next() {
  			fv.Call(args)
  		}
  	})
  }
  
  func BenchmarkCallArgCopy(b *testing.B) {
  	byteArray := func(n int) Value {
  		return Zero(ArrayOf(n, TypeOf(byte(0))))
  	}
  	sizes := [...]struct {
  		fv  Value
  		arg Value
  	}{
  		{ValueOf(func(a [128]byte) {}), byteArray(128)},
  		{ValueOf(func(a [256]byte) {}), byteArray(256)},
  		{ValueOf(func(a [1024]byte) {}), byteArray(1024)},
  		{ValueOf(func(a [4096]byte) {}), byteArray(4096)},
  		{ValueOf(func(a [65536]byte) {}), byteArray(65536)},
  	}
  	for _, size := range sizes {
  		bench := func(b *testing.B) {
  			args := []Value{size.arg}
  			b.SetBytes(int64(size.arg.Len()))
  			b.ResetTimer()
  			b.RunParallel(func(pb *testing.PB) {
  				for pb.Next() {
  					size.fv.Call(args)
  				}
  			})
  		}
  		name := fmt.Sprintf("size=%v", size.arg.Len())
  		b.Run(name, bench)
  	}
  }
  
  func TestMakeFunc(t *testing.T) {
  	f := dummy
  	fv := MakeFunc(TypeOf(f), func(in []Value) []Value { return in })
  	ValueOf(&f).Elem().Set(fv)
  
  	// Call g with small arguments so that there is
  	// something predictable (and different from the
  	// correct results) in those positions on the stack.
  	g := dummy
  	g(1, 2, 3, two{4, 5}, 6, 7, 8)
  
  	// Call constructed function f.
  	i, j, k, l, m, n, o := f(10, 20, 30, two{40, 50}, 60, 70, 80)
  	if i != 10 || j != 20 || k != 30 || l != (two{40, 50}) || m != 60 || n != 70 || o != 80 {
  		t.Errorf("Call returned %d, %d, %d, %v, %d, %g, %d; want 10, 20, 30, [40, 50], 60, 70, 80", i, j, k, l, m, n, o)
  	}
  }
  
  func TestMakeFuncInterface(t *testing.T) {
  	fn := func(i int) int { return i }
  	incr := func(in []Value) []Value {
  		return []Value{ValueOf(int(in[0].Int() + 1))}
  	}
  	fv := MakeFunc(TypeOf(fn), incr)
  	ValueOf(&fn).Elem().Set(fv)
  	if r := fn(2); r != 3 {
  		t.Errorf("Call returned %d, want 3", r)
  	}
  	if r := fv.Call([]Value{ValueOf(14)})[0].Int(); r != 15 {
  		t.Errorf("Call returned %d, want 15", r)
  	}
  	if r := fv.Interface().(func(int) int)(26); r != 27 {
  		t.Errorf("Call returned %d, want 27", r)
  	}
  }
  
  func TestMakeFuncVariadic(t *testing.T) {
  	// Test that variadic arguments are packed into a slice and passed as last arg
  	fn := func(_ int, is ...int) []int { return nil }
  	fv := MakeFunc(TypeOf(fn), func(in []Value) []Value { return in[1:2] })
  	ValueOf(&fn).Elem().Set(fv)
  
  	r := fn(1, 2, 3)
  	if r[0] != 2 || r[1] != 3 {
  		t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
  	}
  
  	r = fn(1, []int{2, 3}...)
  	if r[0] != 2 || r[1] != 3 {
  		t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
  	}
  
  	r = fv.Call([]Value{ValueOf(1), ValueOf(2), ValueOf(3)})[0].Interface().([]int)
  	if r[0] != 2 || r[1] != 3 {
  		t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
  	}
  
  	r = fv.CallSlice([]Value{ValueOf(1), ValueOf([]int{2, 3})})[0].Interface().([]int)
  	if r[0] != 2 || r[1] != 3 {
  		t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
  	}
  
  	f := fv.Interface().(func(int, ...int) []int)
  
  	r = f(1, 2, 3)
  	if r[0] != 2 || r[1] != 3 {
  		t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
  	}
  	r = f(1, []int{2, 3}...)
  	if r[0] != 2 || r[1] != 3 {
  		t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
  	}
  }
  
  type Point struct {
  	x, y int
  }
  
  // This will be index 0.
  func (p Point) AnotherMethod(scale int) int {
  	return -1
  }
  
  // This will be index 1.
  func (p Point) Dist(scale int) int {
  	//println("Point.Dist", p.x, p.y, scale)
  	return p.x*p.x*scale + p.y*p.y*scale
  }
  
  // This will be index 2.
  func (p Point) GCMethod(k int) int {
  	runtime.GC()
  	return k + p.x
  }
  
  // This will be index 3.
  func (p Point) NoArgs() {
  	// Exercise no-argument/no-result paths.
  }
  
  // This will be index 4.
  func (p Point) TotalDist(points ...Point) int {
  	tot := 0
  	for _, q := range points {
  		dx := q.x - p.x
  		dy := q.y - p.y
  		tot += dx*dx + dy*dy // Should call Sqrt, but it's just a test.
  
  	}
  	return tot
  }
  
  func TestMethod(t *testing.T) {
  	// Non-curried method of type.
  	p := Point{3, 4}
  	i := TypeOf(p).Method(1).Func.Call([]Value{ValueOf(p), ValueOf(10)})[0].Int()
  	if i != 250 {
  		t.Errorf("Type Method returned %d; want 250", i)
  	}
  
  	m, ok := TypeOf(p).MethodByName("Dist")
  	if !ok {
  		t.Fatalf("method by name failed")
  	}
  	i = m.Func.Call([]Value{ValueOf(p), ValueOf(11)})[0].Int()
  	if i != 275 {
  		t.Errorf("Type MethodByName returned %d; want 275", i)
  	}
  
  	m, ok = TypeOf(p).MethodByName("NoArgs")
  	if !ok {
  		t.Fatalf("method by name failed")
  	}
  	n := len(m.Func.Call([]Value{ValueOf(p)}))
  	if n != 0 {
  		t.Errorf("NoArgs returned %d values; want 0", n)
  	}
  
  	i = TypeOf(&p).Method(1).Func.Call([]Value{ValueOf(&p), ValueOf(12)})[0].Int()
  	if i != 300 {
  		t.Errorf("Pointer Type Method returned %d; want 300", i)
  	}
  
  	m, ok = TypeOf(&p).MethodByName("Dist")
  	if !ok {
  		t.Fatalf("ptr method by name failed")
  	}
  	i = m.Func.Call([]Value{ValueOf(&p), ValueOf(13)})[0].Int()
  	if i != 325 {
  		t.Errorf("Pointer Type MethodByName returned %d; want 325", i)
  	}
  
  	m, ok = TypeOf(&p).MethodByName("NoArgs")
  	if !ok {
  		t.Fatalf("method by name failed")
  	}
  	n = len(m.Func.Call([]Value{ValueOf(&p)}))
  	if n != 0 {
  		t.Errorf("NoArgs returned %d values; want 0", n)
  	}
  
  	// Curried method of value.
  	tfunc := TypeOf((func(int) int)(nil))
  	v := ValueOf(p).Method(1)
  	if tt := v.Type(); tt != tfunc {
  		t.Errorf("Value Method Type is %s; want %s", tt, tfunc)
  	}
  	i = v.Call([]Value{ValueOf(14)})[0].Int()
  	if i != 350 {
  		t.Errorf("Value Method returned %d; want 350", i)
  	}
  	v = ValueOf(p).MethodByName("Dist")
  	if tt := v.Type(); tt != tfunc {
  		t.Errorf("Value MethodByName Type is %s; want %s", tt, tfunc)
  	}
  	i = v.Call([]Value{ValueOf(15)})[0].Int()
  	if i != 375 {
  		t.Errorf("Value MethodByName returned %d; want 375", i)
  	}
  	v = ValueOf(p).MethodByName("NoArgs")
  	v.Call(nil)
  
  	// Curried method of pointer.
  	v = ValueOf(&p).Method(1)
  	if tt := v.Type(); tt != tfunc {
  		t.Errorf("Pointer Value Method Type is %s; want %s", tt, tfunc)
  	}
  	i = v.Call([]Value{ValueOf(16)})[0].Int()
  	if i != 400 {
  		t.Errorf("Pointer Value Method returned %d; want 400", i)
  	}
  	v = ValueOf(&p).MethodByName("Dist")
  	if tt := v.Type(); tt != tfunc {
  		t.Errorf("Pointer Value MethodByName Type is %s; want %s", tt, tfunc)
  	}
  	i = v.Call([]Value{ValueOf(17)})[0].Int()
  	if i != 425 {
  		t.Errorf("Pointer Value MethodByName returned %d; want 425", i)
  	}
  	v = ValueOf(&p).MethodByName("NoArgs")
  	v.Call(nil)
  
  	// Curried method of interface value.
  	// Have to wrap interface value in a struct to get at it.
  	// Passing it to ValueOf directly would
  	// access the underlying Point, not the interface.
  	var x interface {
  		Dist(int) int
  	} = p
  	pv := ValueOf(&x).Elem()
  	v = pv.Method(0)
  	if tt := v.Type(); tt != tfunc {
  		t.Errorf("Interface Method Type is %s; want %s", tt, tfunc)
  	}
  	i = v.Call([]Value{ValueOf(18)})[0].Int()
  	if i != 450 {
  		t.Errorf("Interface Method returned %d; want 450", i)
  	}
  	v = pv.MethodByName("Dist")
  	if tt := v.Type(); tt != tfunc {
  		t.Errorf("Interface MethodByName Type is %s; want %s", tt, tfunc)
  	}
  	i = v.Call([]Value{ValueOf(19)})[0].Int()
  	if i != 475 {
  		t.Errorf("Interface MethodByName returned %d; want 475", i)
  	}
  }
  
  func TestMethodValue(t *testing.T) {
  	p := Point{3, 4}
  	var i int64
  
  	// Curried method of value.
  	tfunc := TypeOf((func(int) int)(nil))
  	v := ValueOf(p).Method(1)
  	if tt := v.Type(); tt != tfunc {
  		t.Errorf("Value Method Type is %s; want %s", tt, tfunc)
  	}
  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(10)})[0].Int()
  	if i != 250 {
  		t.Errorf("Value Method returned %d; want 250", i)
  	}
  	v = ValueOf(p).MethodByName("Dist")
  	if tt := v.Type(); tt != tfunc {
  		t.Errorf("Value MethodByName Type is %s; want %s", tt, tfunc)
  	}
  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(11)})[0].Int()
  	if i != 275 {
  		t.Errorf("Value MethodByName returned %d; want 275", i)
  	}
  	v = ValueOf(p).MethodByName("NoArgs")
  	ValueOf(v.Interface()).Call(nil)
  	v.Interface().(func())()
  
  	// Curried method of pointer.
  	v = ValueOf(&p).Method(1)
  	if tt := v.Type(); tt != tfunc {
  		t.Errorf("Pointer Value Method Type is %s; want %s", tt, tfunc)
  	}
  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(12)})[0].Int()
  	if i != 300 {
  		t.Errorf("Pointer Value Method returned %d; want 300", i)
  	}
  	v = ValueOf(&p).MethodByName("Dist")
  	if tt := v.Type(); tt != tfunc {
  		t.Errorf("Pointer Value MethodByName Type is %s; want %s", tt, tfunc)
  	}
  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(13)})[0].Int()
  	if i != 325 {
  		t.Errorf("Pointer Value MethodByName returned %d; want 325", i)
  	}
  	v = ValueOf(&p).MethodByName("NoArgs")
  	ValueOf(v.Interface()).Call(nil)
  	v.Interface().(func())()
  
  	// Curried method of pointer to pointer.
  	pp := &p
  	v = ValueOf(&pp).Elem().Method(1)
  	if tt := v.Type(); tt != tfunc {
  		t.Errorf("Pointer Pointer Value Method Type is %s; want %s", tt, tfunc)
  	}
  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(14)})[0].Int()
  	if i != 350 {
  		t.Errorf("Pointer Pointer Value Method returned %d; want 350", i)
  	}
  	v = ValueOf(&pp).Elem().MethodByName("Dist")
  	if tt := v.Type(); tt != tfunc {
  		t.Errorf("Pointer Pointer Value MethodByName Type is %s; want %s", tt, tfunc)
  	}
  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(15)})[0].Int()
  	if i != 375 {
  		t.Errorf("Pointer Pointer Value MethodByName returned %d; want 375", i)
  	}
  
  	// Curried method of interface value.
  	// Have to wrap interface value in a struct to get at it.
  	// Passing it to ValueOf directly would
  	// access the underlying Point, not the interface.
  	var s = struct {
  		X interface {
  			Dist(int) int
  		}
  	}{p}
  	pv := ValueOf(s).Field(0)
  	v = pv.Method(0)
  	if tt := v.Type(); tt != tfunc {
  		t.Errorf("Interface Method Type is %s; want %s", tt, tfunc)
  	}
  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(16)})[0].Int()
  	if i != 400 {
  		t.Errorf("Interface Method returned %d; want 400", i)
  	}
  	v = pv.MethodByName("Dist")
  	if tt := v.Type(); tt != tfunc {
  		t.Errorf("Interface MethodByName Type is %s; want %s", tt, tfunc)
  	}
  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(17)})[0].Int()
  	if i != 425 {
  		t.Errorf("Interface MethodByName returned %d; want 425", i)
  	}
  }
  
  func TestVariadicMethodValue(t *testing.T) {
  	p := Point{3, 4}
  	points := []Point{{20, 21}, {22, 23}, {24, 25}}
  	want := int64(p.TotalDist(points[0], points[1], points[2]))
  
  	// Curried method of value.
  	tfunc := TypeOf((func(...Point) int)(nil))
  	v := ValueOf(p).Method(4)
  	if tt := v.Type(); tt != tfunc {
  		t.Errorf("Variadic Method Type is %s; want %s", tt, tfunc)
  	}
  	i := ValueOf(v.Interface()).Call([]Value{ValueOf(points[0]), ValueOf(points[1]), ValueOf(points[2])})[0].Int()
  	if i != want {
  		t.Errorf("Variadic Method returned %d; want %d", i, want)
  	}
  	i = ValueOf(v.Interface()).CallSlice([]Value{ValueOf(points)})[0].Int()
  	if i != want {
  		t.Errorf("Variadic Method CallSlice returned %d; want %d", i, want)
  	}
  
  	f := v.Interface().(func(...Point) int)
  	i = int64(f(points[0], points[1], points[2]))
  	if i != want {
  		t.Errorf("Variadic Method Interface returned %d; want %d", i, want)
  	}
  	i = int64(f(points...))
  	if i != want {
  		t.Errorf("Variadic Method Interface Slice returned %d; want %d", i, want)
  	}
  }
  
  // Reflect version of $GOROOT/test/method5.go
  
  // Concrete types implementing M method.
  // Smaller than a word, word-sized, larger than a word.
  // Value and pointer receivers.
  
  type Tinter interface {
  	M(int, byte) (byte, int)
  }
  
  type Tsmallv byte
  
  func (v Tsmallv) M(x int, b byte) (byte, int) { return b, x + int(v) }
  
  type Tsmallp byte
  
  func (p *Tsmallp) M(x int, b byte) (byte, int) { return b, x + int(*p) }
  
  type Twordv uintptr
  
  func (v Twordv) M(x int, b byte) (byte, int) { return b, x + int(v) }
  
  type Twordp uintptr
  
  func (p *Twordp) M(x int, b byte) (byte, int) { return b, x + int(*p) }
  
  type Tbigv [2]uintptr
  
  func (v Tbigv) M(x int, b byte) (byte, int) { return b, x + int(v[0]) + int(v[1]) }
  
  type Tbigp [2]uintptr
  
  func (p *Tbigp) M(x int, b byte) (byte, int) { return b, x + int(p[0]) + int(p[1]) }
  
  type tinter interface {
  	m(int, byte) (byte, int)
  }
  
  // Embedding via pointer.
  
  type Tm1 struct {
  	Tm2
  }
  
  type Tm2 struct {
  	*Tm3
  }
  
  type Tm3 struct {
  	*Tm4
  }
  
  type Tm4 struct {
  }
  
  func (t4 Tm4) M(x int, b byte) (byte, int) { return b, x + 40 }
  
  func TestMethod5(t *testing.T) {
  	CheckF := func(name string, f func(int, byte) (byte, int), inc int) {
  		b, x := f(1000, 99)
  		if b != 99 || x != 1000+inc {
  			t.Errorf("%s(1000, 99) = %v, %v, want 99, %v", name, b, x, 1000+inc)
  		}
  	}
  
  	CheckV := func(name string, i Value, inc int) {
  		bx := i.Method(0).Call([]Value{ValueOf(1000), ValueOf(byte(99))})
  		b := bx[0].Interface()
  		x := bx[1].Interface()
  		if b != byte(99) || x != 1000+inc {
  			t.Errorf("direct %s.M(1000, 99) = %v, %v, want 99, %v", name, b, x, 1000+inc)
  		}
  
  		CheckF(name+".M", i.Method(0).Interface().(func(int, byte) (byte, int)), inc)
  	}
  
  	var TinterType = TypeOf(new(Tinter)).Elem()
  
  	CheckI := func(name string, i interface{}, inc int) {
  		v := ValueOf(i)
  		CheckV(name, v, inc)
  		CheckV("(i="+name+")", v.Convert(TinterType), inc)
  	}
  
  	sv := Tsmallv(1)
  	CheckI("sv", sv, 1)
  	CheckI("&sv", &sv, 1)
  
  	sp := Tsmallp(2)
  	CheckI("&sp", &sp, 2)
  
  	wv := Twordv(3)
  	CheckI("wv", wv, 3)
  	CheckI("&wv", &wv, 3)
  
  	wp := Twordp(4)
  	CheckI("&wp", &wp, 4)
  
  	bv := Tbigv([2]uintptr{5, 6})
  	CheckI("bv", bv, 11)
  	CheckI("&bv", &bv, 11)
  
  	bp := Tbigp([2]uintptr{7, 8})
  	CheckI("&bp", &bp, 15)
  
  	t4 := Tm4{}
  	t3 := Tm3{&t4}
  	t2 := Tm2{&t3}
  	t1 := Tm1{t2}
  	CheckI("t4", t4, 40)
  	CheckI("&t4", &t4, 40)
  	CheckI("t3", t3, 40)
  	CheckI("&t3", &t3, 40)
  	CheckI("t2", t2, 40)
  	CheckI("&t2", &t2, 40)
  	CheckI("t1", t1, 40)
  	CheckI("&t1", &t1, 40)
  
  	var tnil Tinter
  	vnil := ValueOf(&tnil).Elem()
  	shouldPanic(func() { vnil.Method(0) })
  }
  
  func TestInterfaceSet(t *testing.T) {
  	p := &Point{3, 4}
  
  	var s struct {
  		I interface{}
  		P interface {
  			Dist(int) int
  		}
  	}
  	sv := ValueOf(&s).Elem()
  	sv.Field(0).Set(ValueOf(p))
  	if q := s.I.(*Point); q != p {
  		t.Errorf("i: have %p want %p", q, p)
  	}
  
  	pv := sv.Field(1)
  	pv.Set(ValueOf(p))
  	if q := s.P.(*Point); q != p {
  		t.Errorf("i: have %p want %p", q, p)
  	}
  
  	i := pv.Method(0).Call([]Value{ValueOf(10)})[0].Int()
  	if i != 250 {
  		t.Errorf("Interface Method returned %d; want 250", i)
  	}
  }
  
  type T1 struct {
  	a string
  	int
  }
  
  func TestAnonymousFields(t *testing.T) {
  	var field StructField
  	var ok bool
  	var t1 T1
  	type1 := TypeOf(t1)
  	if field, ok = type1.FieldByName("int"); !ok {
  		t.Fatal("no field 'int'")
  	}
  	if field.Index[0] != 1 {
  		t.Error("field index should be 1; is", field.Index)
  	}
  }
  
  type FTest struct {
  	s     interface{}
  	name  string
  	index []int
  	value int
  }
  
  type D1 struct {
  	d int
  }
  type D2 struct {
  	d int
  }
  
  type S0 struct {
  	A, B, C int
  	D1
  	D2
  }
  
  type S1 struct {
  	B int
  	S0
  }
  
  type S2 struct {
  	A int
  	*S1
  }
  
  type S1x struct {
  	S1
  }
  
  type S1y struct {
  	S1
  }
  
  type S3 struct {
  	S1x
  	S2
  	D, E int
  	*S1y
  }
  
  type S4 struct {
  	*S4
  	A int
  }
  
  // The X in S6 and S7 annihilate, but they also block the X in S8.S9.
  type S5 struct {
  	S6
  	S7
  	S8
  }
  
  type S6 struct {
  	X int
  }
  
  type S7 S6
  
  type S8 struct {
  	S9
  }
  
  type S9 struct {
  	X int
  	Y int
  }
  
  // The X in S11.S6 and S12.S6 annihilate, but they also block the X in S13.S8.S9.
  type S10 struct {
  	S11
  	S12
  	S13
  }
  
  type S11 struct {
  	S6
  }
  
  type S12 struct {
  	S6
  }
  
  type S13 struct {
  	S8
  }
  
  // The X in S15.S11.S1 and S16.S11.S1 annihilate.
  type S14 struct {
  	S15
  	S16
  }
  
  type S15 struct {
  	S11
  }
  
  type S16 struct {
  	S11
  }
  
  var fieldTests = []FTest{
  	{struct{}{}, "", nil, 0},
  	{struct{}{}, "Foo", nil, 0},
  	{S0{A: 'a'}, "A", []int{0}, 'a'},
  	{S0{}, "D", nil, 0},
  	{S1{S0: S0{A: 'a'}}, "A", []int{1, 0}, 'a'},
  	{S1{B: 'b'}, "B", []int{0}, 'b'},
  	{S1{}, "S0", []int{1}, 0},
  	{S1{S0: S0{C: 'c'}}, "C", []int{1, 2}, 'c'},
  	{S2{A: 'a'}, "A", []int{0}, 'a'},
  	{S2{}, "S1", []int{1}, 0},
  	{S2{S1: &S1{B: 'b'}}, "B", []int{1, 0}, 'b'},
  	{S2{S1: &S1{S0: S0{C: 'c'}}}, "C", []int{1, 1, 2}, 'c'},
  	{S2{}, "D", nil, 0},
  	{S3{}, "S1", nil, 0},
  	{S3{S2: S2{A: 'a'}}, "A", []int{1, 0}, 'a'},
  	{S3{}, "B", nil, 0},
  	{S3{D: 'd'}, "D", []int{2}, 0},
  	{S3{E: 'e'}, "E", []int{3}, 'e'},
  	{S4{A: 'a'}, "A", []int{1}, 'a'},
  	{S4{}, "B", nil, 0},
  	{S5{}, "X", nil, 0},
  	{S5{}, "Y", []int{2, 0, 1}, 0},
  	{S10{}, "X", nil, 0},
  	{S10{}, "Y", []int{2, 0, 0, 1}, 0},
  	{S14{}, "X", nil, 0},
  }
  
  func TestFieldByIndex(t *testing.T) {
  	for _, test := range fieldTests {
  		s := TypeOf(test.s)
  		f := s.FieldByIndex(test.index)
  		if f.Name != "" {
  			if test.index != nil {
  				if f.Name != test.name {
  					t.Errorf("%s.%s found; want %s", s.Name(), f.Name, test.name)
  				}
  			} else {
  				t.Errorf("%s.%s found", s.Name(), f.Name)
  			}
  		} else if len(test.index) > 0 {
  			t.Errorf("%s.%s not found", s.Name(), test.name)
  		}
  
  		if test.value != 0 {
  			v := ValueOf(test.s).FieldByIndex(test.index)
  			if v.IsValid() {
  				if x, ok := v.Interface().(int); ok {
  					if x != test.value {
  						t.Errorf("%s%v is %d; want %d", s.Name(), test.index, x, test.value)
  					}
  				} else {
  					t.Errorf("%s%v value not an int", s.Name(), test.index)
  				}
  			} else {
  				t.Errorf("%s%v value not found", s.Name(), test.index)
  			}
  		}
  	}
  }
  
  func TestFieldByName(t *testing.T) {
  	for _, test := range fieldTests {
  		s := TypeOf(test.s)
  		f, found := s.FieldByName(test.name)
  		if found {
  			if test.index != nil {
  				// Verify field depth and index.
  				if len(f.Index) != len(test.index) {
  					t.Errorf("%s.%s depth %d; want %d: %v vs %v", s.Name(), test.name, len(f.Index), len(test.index), f.Index, test.index)
  				} else {
  					for i, x := range f.Index {
  						if x != test.index[i] {
  							t.Errorf("%s.%s.Index[%d] is %d; want %d", s.Name(), test.name, i, x, test.index[i])
  						}
  					}
  				}
  			} else {
  				t.Errorf("%s.%s found", s.Name(), f.Name)
  			}
  		} else if len(test.index) > 0 {
  			t.Errorf("%s.%s not found", s.Name(), test.name)
  		}
  
  		if test.value != 0 {
  			v := ValueOf(test.s).FieldByName(test.name)
  			if v.IsValid() {
  				if x, ok := v.Interface().(int); ok {
  					if x != test.value {
  						t.Errorf("%s.%s is %d; want %d", s.Name(), test.name, x, test.value)
  					}
  				} else {
  					t.Errorf("%s.%s value not an int", s.Name(), test.name)
  				}
  			} else {
  				t.Errorf("%s.%s value not found", s.Name(), test.name)
  			}
  		}
  	}
  }
  
  func TestImportPath(t *testing.T) {
  	tests := []struct {
  		t    Type
  		path string
  	}{
  		{TypeOf(&base64.Encoding{}).Elem(), "encoding/base64"},
  		{TypeOf(int(0)), ""},
  		{TypeOf(int8(0)), ""},
  		{TypeOf(int16(0)), ""},
  		{TypeOf(int32(0)), ""},
  		{TypeOf(int64(0)), ""},
  		{TypeOf(uint(0)), ""},
  		{TypeOf(uint8(0)), ""},
  		{TypeOf(uint16(0)), ""},
  		{TypeOf(uint32(0)), ""},
  		{TypeOf(uint64(0)), ""},
  		{TypeOf(uintptr(0)), ""},
  		{TypeOf(float32(0)), ""},
  		{TypeOf(float64(0)), ""},
  		{TypeOf(complex64(0)), ""},
  		{TypeOf(complex128(0)), ""},
  		{TypeOf(byte(0)), ""},
  		{TypeOf(rune(0)), ""},
  		{TypeOf([]byte(nil)), ""},
  		{TypeOf([]rune(nil)), ""},
  		{TypeOf(string("")), ""},
  		{TypeOf((*interface{})(nil)).Elem(), ""},
  		{TypeOf((*byte)(nil)), ""},
  		{TypeOf((*rune)(nil)), ""},
  		{TypeOf((*int64)(nil)), ""},
  		{TypeOf(map[string]int{}), ""},
  		{TypeOf((*error)(nil)).Elem(), ""},
  		{TypeOf((*Point)(nil)), ""},
  		{TypeOf((*Point)(nil)).Elem(), "reflect_test"},
  	}
  	for _, test := range tests {
  		if path := test.t.PkgPath(); path != test.path {
  			t.Errorf("%v.PkgPath() = %q, want %q", test.t, path, test.path)
  		}
  	}
  }
  
  func TestFieldPkgPath(t *testing.T) {
  	typ := TypeOf(struct {
  		Exported   string
  		unexported string
  		OtherPkgFields
  	}{})
  
  	type pkgpathTest struct {
  		index     []int
  		pkgPath   string
  		anonymous bool
  	}
  
  	checkPkgPath := func(name string, s []pkgpathTest) {
  		for _, test := range s {
  			f := typ.FieldByIndex(test.index)
  			if got, want := f.PkgPath, test.pkgPath; got != want {
  				t.Errorf("%s: Field(%d).PkgPath = %q, want %q", name, test.index, got, want)
  			}
  			if got, want := f.Anonymous, test.anonymous; got != want {
  				t.Errorf("%s: Field(%d).Anonymous = %v, want %v", name, test.index, got, want)
  			}
  		}
  	}
  
  	checkPkgPath("testStruct", []pkgpathTest{
  		{[]int{0}, "", false},             // Exported
  		{[]int{1}, "reflect_test", false}, // unexported
  		{[]int{2}, "", true},              // OtherPkgFields
  		{[]int{2, 0}, "", false},          // OtherExported
  		{[]int{2, 1}, "reflect", false},   // otherUnexported
  	})
  
  	type localOtherPkgFields OtherPkgFields
  	typ = TypeOf(localOtherPkgFields{})
  	checkPkgPath("localOtherPkgFields", []pkgpathTest{
  		{[]int{0}, "", false},        // OtherExported
  		{[]int{1}, "reflect", false}, // otherUnexported
  	})
  }
  
  func TestVariadicType(t *testing.T) {
  	// Test example from Type documentation.
  	var f func(x int, y ...float64)
  	typ := TypeOf(f)
  	if typ.NumIn() == 2 && typ.In(0) == TypeOf(int(0)) {
  		sl := typ.In(1)
  		if sl.Kind() == Slice {
  			if sl.Elem() == TypeOf(0.0) {
  				// ok
  				return
  			}
  		}
  	}
  
  	// Failed
  	t.Errorf("want NumIn() = 2, In(0) = int, In(1) = []float64")
  	s := fmt.Sprintf("have NumIn() = %d", typ.NumIn())
  	for i := 0; i < typ.NumIn(); i++ {
  		s += fmt.Sprintf(", In(%d) = %s", i, typ.In(i))
  	}
  	t.Error(s)
  }
  
  type inner struct {
  	x int
  }
  
  type outer struct {
  	y int
  	inner
  }
  
  func (*inner) M() {}
  func (*outer) M() {}
  
  func TestNestedMethods(t *testing.T) {
  	typ := TypeOf((*outer)(nil))
  	if typ.NumMethod() != 1 || typ.Method(0).Func.Pointer() != ValueOf((*outer).M).Pointer() {
  		t.Errorf("Wrong method table for outer: (M=%p)", (*outer).M)
  		for i := 0; i < typ.NumMethod(); i++ {
  			m := typ.Method(i)
  			t.Errorf("\t%d: %s %#x\n", i, m.Name, m.Func.Pointer())
  		}
  	}
  }
  
  type unexp struct{}
  
  func (*unexp) f() (int32, int8) { return 7, 7 }
  func (*unexp) g() (int64, int8) { return 8, 8 }
  
  type unexpI interface {
  	f() (int32, int8)
  }
  
  var unexpi unexpI = new(unexp)
  
  func TestUnexportedMethods(t *testing.T) {
  	typ := TypeOf(unexpi)
  
  	if got := typ.NumMethod(); got != 0 {
  		t.Errorf("NumMethod=%d, want 0 satisfied methods", got)
  	}
  }
  
  type InnerInt struct {
  	X int
  }
  
  type OuterInt struct {
  	Y int
  	InnerInt
  }
  
  func (i *InnerInt) M() int {
  	return i.X
  }
  
  func TestEmbeddedMethods(t *testing.T) {
  	typ := TypeOf((*OuterInt)(nil))
  	if typ.NumMethod() != 1 || typ.Method(0).Func.Pointer() != ValueOf((*OuterInt).M).Pointer() {
  		t.Errorf("Wrong method table for OuterInt: (m=%p)", (*OuterInt).M)
  		for i := 0; i < typ.NumMethod(); i++ {
  			m := typ.Method(i)
  			t.Errorf("\t%d: %s %#x\n", i, m.Name, m.Func.Pointer())
  		}
  	}
  
  	i := &InnerInt{3}
  	if v := ValueOf(i).Method(0).Call(nil)[0].Int(); v != 3 {
  		t.Errorf("i.M() = %d, want 3", v)
  	}
  
  	o := &OuterInt{1, InnerInt{2}}
  	if v := ValueOf(o).Method(0).Call(nil)[0].Int(); v != 2 {
  		t.Errorf("i.M() = %d, want 2", v)
  	}
  
  	f := (*OuterInt).M
  	if v := f(o); v != 2 {
  		t.Errorf("f(o) = %d, want 2", v)
  	}
  }
  
  type FuncDDD func(...interface{}) error
  
  func (f FuncDDD) M() {}
  
  func TestNumMethodOnDDD(t *testing.T) {
  	rv := ValueOf((FuncDDD)(nil))
  	if n := rv.NumMethod(); n != 1 {
  		t.Fatalf("NumMethod()=%d, want 1", n)
  	}
  }
  
  func TestPtrTo(t *testing.T) {
  	// This block of code means that the ptrToThis field of the
  	// reflect data for *unsafe.Pointer is non zero, see
  	// https://golang.org/issue/19003
  	var x unsafe.Pointer
  	var y = &x
  	var z = &y
  
  	var i int
  
  	typ := TypeOf(z)
  	for i = 0; i < 100; i++ {
  		typ = PtrTo(typ)
  	}
  	for i = 0; i < 100; i++ {
  		typ = typ.Elem()
  	}
  	if typ != TypeOf(z) {
  		t.Errorf("after 100 PtrTo and Elem, have %s, want %s", typ, TypeOf(z))
  	}
  }
  
  func TestPtrToGC(t *testing.T) {
  	type T *uintptr
  	tt := TypeOf(T(nil))
  	pt := PtrTo(tt)
  	const n = 100
  	var x []interface{}
  	for i := 0; i < n; i++ {
  		v := New(pt)
  		p := new(*uintptr)
  		*p = new(uintptr)
  		**p = uintptr(i)
  		v.Elem().Set(ValueOf(p).Convert(pt))
  		x = append(x, v.Interface())
  	}
  	runtime.GC()
  
  	for i, xi := range x {
  		k := ValueOf(xi).Elem().Elem().Elem().Interface().(uintptr)
  		if k != uintptr(i) {
  			t.Errorf("lost x[%d] = %d, want %d", i, k, i)
  		}
  	}
  }
  
  func BenchmarkPtrTo(b *testing.B) {
  	// Construct a type with a zero ptrToThis.
  	type T struct{ int }
  	t := SliceOf(TypeOf(T{}))
  	ptrToThis := ValueOf(t).Elem().FieldByName("ptrToThis")
  	if !ptrToThis.IsValid() {
  		b.Fatalf("%v has no ptrToThis field; was it removed from rtype?", t)
  	}
  	if ptrToThis.Int() != 0 {
  		b.Fatalf("%v.ptrToThis unexpectedly nonzero", t)
  	}
  	b.ResetTimer()
  
  	// Now benchmark calling PtrTo on it: we'll have to hit the ptrMap cache on
  	// every call.
  	b.RunParallel(func(pb *testing.PB) {
  		for pb.Next() {
  			PtrTo(t)
  		}
  	})
  }
  
  func TestAddr(t *testing.T) {
  	var p struct {
  		X, Y int
  	}
  
  	v := ValueOf(&p)
  	v = v.Elem()
  	v = v.Addr()
  	v = v.Elem()
  	v = v.Field(0)
  	v.SetInt(2)
  	if p.X != 2 {
  		t.Errorf("Addr.Elem.Set failed to set value")
  	}
  
  	// Again but take address of the ValueOf value.
  	// Exercises generation of PtrTypes not present in the binary.
  	q := &p
  	v = ValueOf(&q).Elem()
  	v = v.Addr()
  	v = v.Elem()
  	v = v.Elem()
  	v = v.Addr()
  	v = v.Elem()
  	v = v.Field(0)
  	v.SetInt(3)
  	if p.X != 3 {
  		t.Errorf("Addr.Elem.Set failed to set value")
  	}
  
  	// Starting without pointer we should get changed value
  	// in interface.
  	qq := p
  	v = ValueOf(&qq).Elem()
  	v0 := v
  	v = v.Addr()
  	v = v.Elem()
  	v = v.Field(0)
  	v.SetInt(4)
  	if p.X != 3 { // should be unchanged from last time
  		t.Errorf("somehow value Set changed original p")
  	}
  	p = v0.Interface().(struct {
  		X, Y int
  	})
  	if p.X != 4 {
  		t.Errorf("Addr.Elem.Set valued to set value in top value")
  	}
  
  	// Verify that taking the address of a type gives us a pointer
  	// which we can convert back using the usual interface
  	// notation.
  	var s struct {
  		B *bool
  	}
  	ps := ValueOf(&s).Elem().Field(0).Addr().Interface()
  	*(ps.(**bool)) = new(bool)
  	if s.B == nil {
  		t.Errorf("Addr.Interface direct assignment failed")
  	}
  }
  
  func noAlloc(t *testing.T, n int, f func(int)) {
  	if testing.Short() {
  		t.Skip("skipping malloc count in short mode")
  	}
  	if runtime.GOMAXPROCS(0) > 1 {
  		t.Skip("skipping; GOMAXPROCS>1")
  	}
  	i := -1
  	allocs := testing.AllocsPerRun(n, func() {
  		f(i)
  		i++
  	})
  	if allocs > 0 {
  		t.Errorf("%d iterations: got %v mallocs, want 0", n, allocs)
  	}
  }
  
  func TestAllocations(t *testing.T) {
  	noAlloc(t, 100, func(j int) {
  		var i interface{}
  		var v Value
  
  		// We can uncomment this when compiler escape analysis
  		// is good enough to see that the integer assigned to i
  		// does not escape and therefore need not be allocated.
  		//
  		// i = 42 + j
  		// v = ValueOf(i)
  		// if int(v.Int()) != 42+j {
  		// 	panic("wrong int")
  		// }
  
  		i = func(j int) int { return j }
  		v = ValueOf(i)
  		if v.Interface().(func(int) int)(j) != j {
  			panic("wrong result")
  		}
  	})
  }
  
  func TestSmallNegativeInt(t *testing.T) {
  	i := int16(-1)
  	v := ValueOf(i)
  	if v.Int() != -1 {
  		t.Errorf("int16(-1).Int() returned %v", v.Int())
  	}
  }
  
  func TestIndex(t *testing.T) {
  	xs := []byte{1, 2, 3, 4, 5, 6, 7, 8}
  	v := ValueOf(xs).Index(3).Interface().(byte)
  	if v != xs[3] {
  		t.Errorf("xs.Index(3) = %v; expected %v", v, xs[3])
  	}
  	xa := [8]byte{10, 20, 30, 40, 50, 60, 70, 80}
  	v = ValueOf(xa).Index(2).Interface().(byte)
  	if v != xa[2] {
  		t.Errorf("xa.Index(2) = %v; expected %v", v, xa[2])
  	}
  	s := "0123456789"
  	v = ValueOf(s).Index(3).Interface().(byte)
  	if v != s[3] {
  		t.Errorf("s.Index(3) = %v; expected %v", v, s[3])
  	}
  }
  
  func TestSlice(t *testing.T) {
  	xs := []int{1, 2, 3, 4, 5, 6, 7, 8}
  	v := ValueOf(xs).Slice(3, 5).Interface().([]int)
  	if len(v) != 2 {
  		t.Errorf("len(xs.Slice(3, 5)) = %d", len(v))
  	}
  	if cap(v) != 5 {
  		t.Errorf("cap(xs.Slice(3, 5)) = %d", cap(v))
  	}
  	if !DeepEqual(v[0:5], xs[3:]) {
  		t.Errorf("xs.Slice(3, 5)[0:5] = %v", v[0:5])
  	}
  	xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80}
  	v = ValueOf(&xa).Elem().Slice(2, 5).Interface().([]int)
  	if len(v) != 3 {
  		t.Errorf("len(xa.Slice(2, 5)) = %d", len(v))
  	}
  	if cap(v) != 6 {
  		t.Errorf("cap(xa.Slice(2, 5)) = %d", cap(v))
  	}
  	if !DeepEqual(v[0:6], xa[2:]) {
  		t.Errorf("xs.Slice(2, 5)[0:6] = %v", v[0:6])
  	}
  	s := "0123456789"
  	vs := ValueOf(s).Slice(3, 5).Interface().(string)
  	if vs != s[3:5] {
  		t.Errorf("s.Slice(3, 5) = %q; expected %q", vs, s[3:5])
  	}
  
  	rv := ValueOf(&xs).Elem()
  	rv = rv.Slice(3, 4)
  	ptr2 := rv.Pointer()
  	rv = rv.Slice(5, 5)
  	ptr3 := rv.Pointer()
  	if ptr3 != ptr2 {
  		t.Errorf("xs.Slice(3,4).Slice3(5,5).Pointer() = %#x, want %#x", ptr3, ptr2)
  	}
  }
  
  func TestSlice3(t *testing.T) {
  	xs := []int{1, 2, 3, 4, 5, 6, 7, 8}
  	v := ValueOf(xs).Slice3(3, 5, 7).Interface().([]int)
  	if len(v) != 2 {
  		t.Errorf("len(xs.Slice3(3, 5, 7)) = %d", len(v))
  	}
  	if cap(v) != 4 {
  		t.Errorf("cap(xs.Slice3(3, 5, 7)) = %d", cap(v))
  	}
  	if !DeepEqual(v[0:4], xs[3:7:7]) {
  		t.Errorf("xs.Slice3(3, 5, 7)[0:4] = %v", v[0:4])
  	}
  	rv := ValueOf(&xs).Elem()
  	shouldPanic(func() { rv.Slice3(1, 2, 1) })
  	shouldPanic(func() { rv.Slice3(1, 1, 11) })
  	shouldPanic(func() { rv.Slice3(2, 2, 1) })
  
  	xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80}
  	v = ValueOf(&xa).Elem().Slice3(2, 5, 6).Interface().([]int)
  	if len(v) != 3 {
  		t.Errorf("len(xa.Slice(2, 5, 6)) = %d", len(v))
  	}
  	if cap(v) != 4 {
  		t.Errorf("cap(xa.Slice(2, 5, 6)) = %d", cap(v))
  	}
  	if !DeepEqual(v[0:4], xa[2:6:6]) {
  		t.Errorf("xs.Slice(2, 5, 6)[0:4] = %v", v[0:4])
  	}
  	rv = ValueOf(&xa).Elem()
  	shouldPanic(func() { rv.Slice3(1, 2, 1) })
  	shouldPanic(func() { rv.Slice3(1, 1, 11) })
  	shouldPanic(func() { rv.Slice3(2, 2, 1) })
  
  	s := "hello world"
  	rv = ValueOf(&s).Elem()
  	shouldPanic(func() { rv.Slice3(1, 2, 3) })
  
  	rv = ValueOf(&xs).Elem()
  	rv = rv.Slice3(3, 5, 7)
  	ptr2 := rv.Pointer()
  	rv = rv.Slice3(4, 4, 4)
  	ptr3 := rv.Pointer()
  	if ptr3 != ptr2 {
  		t.Errorf("xs.Slice3(3,5,7).Slice3(4,4,4).Pointer() = %#x, want %#x", ptr3, ptr2)
  	}
  }
  
  func TestSetLenCap(t *testing.T) {
  	xs := []int{1, 2, 3, 4, 5, 6, 7, 8}
  	xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80}
  
  	vs := ValueOf(&xs).Elem()
  	shouldPanic(func() { vs.SetLen(10) })
  	shouldPanic(func() { vs.SetCap(10) })
  	shouldPanic(func() { vs.SetLen(-1) })
  	shouldPanic(func() { vs.SetCap(-1) })
  	shouldPanic(func() { vs.SetCap(6) }) // smaller than len
  	vs.SetLen(5)
  	if len(xs) != 5 || cap(xs) != 8 {
  		t.Errorf("after SetLen(5), len, cap = %d, %d, want 5, 8", len(xs), cap(xs))
  	}
  	vs.SetCap(6)
  	if len(xs) != 5 || cap(xs) != 6 {
  		t.Errorf("after SetCap(6), len, cap = %d, %d, want 5, 6", len(xs), cap(xs))
  	}
  	vs.SetCap(5)
  	if len(xs) != 5 || cap(xs) != 5 {
  		t.Errorf("after SetCap(5), len, cap = %d, %d, want 5, 5", len(xs), cap(xs))
  	}
  	shouldPanic(func() { vs.SetCap(4) }) // smaller than len
  	shouldPanic(func() { vs.SetLen(6) }) // bigger than cap
  
  	va := ValueOf(&xa).Elem()
  	shouldPanic(func() { va.SetLen(8) })
  	shouldPanic(func() { va.SetCap(8) })
  }
  
  func TestVariadic(t *testing.T) {
  	var b bytes.Buffer
  	V := ValueOf
  
  	b.Reset()
  	V(fmt.Fprintf).Call([]Value{V(&b), V("%s, %d world"), V("hello"), V(42)})
  	if b.String() != "hello, 42 world" {
  		t.Errorf("after Fprintf Call: %q != %q", b.String(), "hello 42 world")
  	}
  
  	b.Reset()
  	V(fmt.Fprintf).CallSlice([]Value{V(&b), V("%s, %d world"), V([]interface{}{"hello", 42})})
  	if b.String() != "hello, 42 world" {
  		t.Errorf("after Fprintf CallSlice: %q != %q", b.String(), "hello 42 world")
  	}
  }
  
  func TestFuncArg(t *testing.T) {
  	f1 := func(i int, f func(int) int) int { return f(i) }
  	f2 := func(i int) int { return i + 1 }
  	r := ValueOf(f1).Call([]Value{ValueOf(100), ValueOf(f2)})
  	if r[0].Int() != 101 {
  		t.Errorf("function returned %d, want 101", r[0].Int())
  	}
  }
  
  func TestStructArg(t *testing.T) {
  	type padded struct {
  		B string
  		C int32
  	}
  	var (
  		gotA  padded
  		gotB  uint32
  		wantA = padded{"3", 4}
  		wantB = uint32(5)
  	)
  	f := func(a padded, b uint32) {
  		gotA, gotB = a, b
  	}
  	ValueOf(f).Call([]Value{ValueOf(wantA), ValueOf(wantB)})
  	if gotA != wantA || gotB != wantB {
  		t.Errorf("function called with (%v, %v), want (%v, %v)", gotA, gotB, wantA, wantB)
  	}
  }
  
  var tagGetTests = []struct {
  	Tag   StructTag
  	Key   string
  	Value string
  }{
  	{`protobuf:"PB(1,2)"`, `protobuf`, `PB(1,2)`},
  	{`protobuf:"PB(1,2)"`, `foo`, ``},
  	{`protobuf:"PB(1,2)"`, `rotobuf`, ``},
  	{`protobuf:"PB(1,2)" json:"name"`, `json`, `name`},
  	{`protobuf:"PB(1,2)" json:"name"`, `protobuf`, `PB(1,2)`},
  	{`k0:"values contain spaces" k1:"and\ttabs"`, "k0", "values contain spaces"},
  	{`k0:"values contain spaces" k1:"and\ttabs"`, "k1", "and\ttabs"},
  }
  
  func TestTagGet(t *testing.T) {
  	for _, tt := range tagGetTests {
  		if v := tt.Tag.Get(tt.Key); v != tt.Value {
  			t.Errorf("StructTag(%#q).Get(%#q) = %#q, want %#q", tt.Tag, tt.Key, v, tt.Value)
  		}
  	}
  }
  
  func TestBytes(t *testing.T) {
  	type B []byte
  	x := B{1, 2, 3, 4}
  	y := ValueOf(x).Bytes()
  	if !bytes.Equal(x, y) {
  		t.Fatalf("ValueOf(%v).Bytes() = %v", x, y)
  	}
  	if &x[0] != &y[0] {
  		t.Errorf("ValueOf(%p).Bytes() = %p", &x[0], &y[0])
  	}
  }
  
  func TestSetBytes(t *testing.T) {
  	type B []byte
  	var x B
  	y := []byte{1, 2, 3, 4}
  	ValueOf(&x).Elem().SetBytes(y)
  	if !bytes.Equal(x, y) {
  		t.Fatalf("ValueOf(%v).Bytes() = %v", x, y)
  	}
  	if &x[0] != &y[0] {
  		t.Errorf("ValueOf(%p).Bytes() = %p", &x[0], &y[0])
  	}
  }
  
  type Private struct {
  	x int
  	y **int
  	Z int
  }
  
  func (p *Private) m() {
  }
  
  type private struct {
  	Z int
  	z int
  	S string
  	A [1]Private
  	T []Private
  }
  
  func (p *private) P() {
  }
  
  type Public struct {
  	X int
  	Y **int
  	private
  }
  
  func (p *Public) M() {
  }
  
  func TestUnexported(t *testing.T) {
  	var pub Public
  	pub.S = "S"
  	pub.T = pub.A[:]
  	v := ValueOf(&pub)
  	isValid(v.Elem().Field(0))
  	isValid(v.Elem().Field(1))
  	isValid(v.Elem().Field(2))
  	isValid(v.Elem().FieldByName("X"))
  	isValid(v.Elem().FieldByName("Y"))
  	isValid(v.Elem().FieldByName("Z"))
  	isValid(v.Type().Method(0).Func)
  	m, _ := v.Type().MethodByName("M")
  	isValid(m.Func)
  	m, _ = v.Type().MethodByName("P")
  	isValid(m.Func)
  	isNonNil(v.Elem().Field(0).Interface())
  	isNonNil(v.Elem().Field(1).Interface())
  	isNonNil(v.Elem().Field(2).Field(2).Index(0))
  	isNonNil(v.Elem().FieldByName("X").Interface())
  	isNonNil(v.Elem().FieldByName("Y").Interface())
  	isNonNil(v.Elem().FieldByName("Z").Interface())
  	isNonNil(v.Elem().FieldByName("S").Index(0).Interface())
  	isNonNil(v.Type().Method(0).Func.Interface())
  	m, _ = v.Type().MethodByName("P")
  	isNonNil(m.Func.Interface())
  
  	var priv Private
  	v = ValueOf(&priv)
  	isValid(v.Elem().Field(0))
  	isValid(v.Elem().Field(1))
  	isValid(v.Elem().FieldByName("x"))
  	isValid(v.Elem().FieldByName("y"))
  	shouldPanic(func() { v.Elem().Field(0).Interface() })
  	shouldPanic(func() { v.Elem().Field(1).Interface() })
  	shouldPanic(func() { v.Elem().FieldByName("x").Interface() })
  	shouldPanic(func() { v.Elem().FieldByName("y").Interface() })
  	shouldPanic(func() { v.Type().Method(0) })
  }
  
  func TestSetPanic(t *testing.T) {
  	ok := func(f func()) { f() }
  	bad := shouldPanic
  	clear := func(v Value) { v.Set(Zero(v.Type())) }
  
  	type t0 struct {
  		W int
  	}
  
  	type t1 struct {
  		Y int
  		t0
  	}
  
  	type T2 struct {
  		Z       int
  		namedT0 t0
  	}
  
  	type T struct {
  		X int
  		t1
  		T2
  		NamedT1 t1
  		NamedT2 T2
  		namedT1 t1
  		namedT2 T2
  	}
  
  	// not addressable
  	v := ValueOf(T{})
  	bad(func() { clear(v.Field(0)) })                   // .X
  	bad(func() { clear(v.Field(1)) })                   // .t1
  	bad(func() { clear(v.Field(1).Field(0)) })          // .t1.Y
  	bad(func() { clear(v.Field(1).Field(1)) })          // .t1.t0
  	bad(func() { clear(v.Field(1).Field(1).Field(0)) }) // .t1.t0.W
  	bad(func() { clear(v.Field(2)) })                   // .T2
  	bad(func() { clear(v.Field(2).Field(0)) })          // .T2.Z
  	bad(func() { clear(v.Field(2).Field(1)) })          // .T2.namedT0
  	bad(func() { clear(v.Field(2).Field(1).Field(0)) }) // .T2.namedT0.W
  	bad(func() { clear(v.Field(3)) })                   // .NamedT1
  	bad(func() { clear(v.Field(3).Field(0)) })          // .NamedT1.Y
  	bad(func() { clear(v.Field(3).Field(1)) })          // .NamedT1.t0
  	bad(func() { clear(v.Field(3).Field(1).Field(0)) }) // .NamedT1.t0.W
  	bad(func() { clear(v.Field(4)) })                   // .NamedT2
  	bad(func() { clear(v.Field(4).Field(0)) })          // .NamedT2.Z
  	bad(func() { clear(v.Field(4).Field(1)) })          // .NamedT2.namedT0
  	bad(func() { clear(v.Field(4).Field(1).Field(0)) }) // .NamedT2.namedT0.W
  	bad(func() { clear(v.Field(5)) })                   // .namedT1
  	bad(func() { clear(v.Field(5).Field(0)) })          // .namedT1.Y
  	bad(func() { clear(v.Field(5).Field(1)) })          // .namedT1.t0
  	bad(func() { clear(v.Field(5).Field(1).Field(0)) }) // .namedT1.t0.W
  	bad(func() { clear(v.Field(6)) })                   // .namedT2
  	bad(func() { clear(v.Field(6).Field(0)) })          // .namedT2.Z
  	bad(func() { clear(v.Field(6).Field(1)) })          // .namedT2.namedT0
  	bad(func() { clear(v.Field(6).Field(1).Field(0)) }) // .namedT2.namedT0.W
  
  	// addressable
  	v = ValueOf(&T{}).Elem()
  	ok(func() { clear(v.Field(0)) })                    // .X
  	bad(func() { clear(v.Field(1)) })                   // .t1
  	ok(func() { clear(v.Field(1).Field(0)) })           // .t1.Y
  	bad(func() { clear(v.Field(1).Field(1)) })          // .t1.t0
  	ok(func() { clear(v.Field(1).Field(1).Field(0)) })  // .t1.t0.W
  	ok(func() { clear(v.Field(2)) })                    // .T2
  	ok(func() { clear(v.Field(2).Field(0)) })           // .T2.Z
  	bad(func() { clear(v.Field(2).Field(1)) })          // .T2.namedT0
  	bad(func() { clear(v.Field(2).Field(1).Field(0)) }) // .T2.namedT0.W
  	ok(func() { clear(v.Field(3)) })                    // .NamedT1
  	ok(func() { clear(v.Field(3).Field(0)) })           // .NamedT1.Y
  	bad(func() { clear(v.Field(3).Field(1)) })          // .NamedT1.t0
  	ok(func() { clear(v.Field(3).Field(1).Field(0)) })  // .NamedT1.t0.W
  	ok(func() { clear(v.Field(4)) })                    // .NamedT2
  	ok(func() { clear(v.Field(4).Field(0)) })           // .NamedT2.Z
  	bad(func() { clear(v.Field(4).Field(1)) })          // .NamedT2.namedT0
  	bad(func() { clear(v.Field(4).Field(1).Field(0)) }) // .NamedT2.namedT0.W
  	bad(func() { clear(v.Field(5)) })                   // .namedT1
  	bad(func() { clear(v.Field(5).Field(0)) })          // .namedT1.Y
  	bad(func() { clear(v.Field(5).Field(1)) })          // .namedT1.t0
  	bad(func() { clear(v.Field(5).Field(1).Field(0)) }) // .namedT1.t0.W
  	bad(func() { clear(v.Field(6)) })                   // .namedT2
  	bad(func() { clear(v.Field(6).Field(0)) })          // .namedT2.Z
  	bad(func() { clear(v.Field(6).Field(1)) })          // .namedT2.namedT0
  	bad(func() { clear(v.Field(6).Field(1).Field(0)) }) // .namedT2.namedT0.W
  }
  
  type timp int
  
  func (t timp) W() {}
  func (t timp) Y() {}
  func (t timp) w() {}
  func (t timp) y() {}
  
  func TestCallPanic(t *testing.T) {
  	type t0 interface {
  		W()
  		w()
  	}
  	type T1 interface {
  		Y()
  		y()
  	}
  	type T2 struct {
  		T1
  		t0
  	}
  	type T struct {
  		t0 // 0
  		T1 // 1
  
  		NamedT0 t0 // 2
  		NamedT1 T1 // 3
  		NamedT2 T2 // 4
  
  		namedT0 t0 // 5
  		namedT1 T1 // 6
  		namedT2 T2 // 7
  	}
  	ok := func(f func()) { f() }
  	bad := shouldPanic
  	call := func(v Value) { v.Call(nil) }
  
  	i := timp(0)
  	v := ValueOf(T{i, i, i, i, T2{i, i}, i, i, T2{i, i}})
  	ok(func() { call(v.Field(0).Method(0)) })         // .t0.W
  	ok(func() { call(v.Field(0).Elem().Method(0)) })  // .t0.W
  	bad(func() { call(v.Field(0).Method(1)) })        // .t0.w
  	bad(func() { call(v.Field(0).Elem().Method(2)) }) // .t0.w
  	ok(func() { call(v.Field(1).Method(0)) })         // .T1.Y
  	ok(func() { call(v.Field(1).Elem().Method(0)) })  // .T1.Y
  	bad(func() { call(v.Field(1).Method(1)) })        // .T1.y
  	bad(func() { call(v.Field(1).Elem().Method(2)) }) // .T1.y
  
  	ok(func() { call(v.Field(2).Method(0)) })         // .NamedT0.W
  	ok(func() { call(v.Field(2).Elem().Method(0)) })  // .NamedT0.W
  	bad(func() { call(v.Field(2).Method(1)) })        // .NamedT0.w
  	bad(func() { call(v.Field(2).Elem().Method(2)) }) // .NamedT0.w
  
  	ok(func() { call(v.Field(3).Method(0)) })         // .NamedT1.Y
  	ok(func() { call(v.Field(3).Elem().Method(0)) })  // .NamedT1.Y
  	bad(func() { call(v.Field(3).Method(1)) })        // .NamedT1.y
  	bad(func() { call(v.Field(3).Elem().Method(3)) }) // .NamedT1.y
  
  	ok(func() { call(v.Field(4).Field(0).Method(0)) })        // .NamedT2.T1.Y
  	ok(func() { call(v.Field(4).Field(0).Elem().Method(0)) }) // .NamedT2.T1.W
  	ok(func() { call(v.Field(4).Field(1).Method(0)) })        // .NamedT2.t0.W
  	ok(func() { call(v.Field(4).Field(1).Elem().Method(0)) }) // .NamedT2.t0.W
  
  	bad(func() { call(v.Field(5).Method(0)) })        // .namedT0.W
  	bad(func() { call(v.Field(5).Elem().Method(0)) }) // .namedT0.W
  	bad(func() { call(v.Field(5).Method(1)) })        // .namedT0.w
  	bad(func() { call(v.Field(5).Elem().Method(2)) }) // .namedT0.w
  
  	bad(func() { call(v.Field(6).Method(0)) })        // .namedT1.Y
  	bad(func() { call(v.Field(6).Elem().Method(0)) }) // .namedT1.Y
  	bad(func() { call(v.Field(6).Method(0)) })        // .namedT1.y
  	bad(func() { call(v.Field(6).Elem().Method(0)) }) // .namedT1.y
  
  	bad(func() { call(v.Field(7).Field(0).Method(0)) })        // .namedT2.T1.Y
  	bad(func() { call(v.Field(7).Field(0).Elem().Method(0)) }) // .namedT2.T1.W
  	bad(func() { call(v.Field(7).Field(1).Method(0)) })        // .namedT2.t0.W
  	bad(func() { call(v.Field(7).Field(1).Elem().Method(0)) }) // .namedT2.t0.W
  }
  
  func shouldPanic(f func()) {
  	defer func() {
  		if recover() == nil {
  			panic("did not panic")
  		}
  	}()
  	f()
  }
  
  func isNonNil(x interface{}) {
  	if x == nil {
  		panic("nil interface")
  	}
  }
  
  func isValid(v Value) {
  	if !v.IsValid() {
  		panic("zero Value")
  	}
  }
  
  func TestAlias(t *testing.T) {
  	x := string("hello")
  	v := ValueOf(&x).Elem()
  	oldvalue := v.Interface()
  	v.SetString("world")
  	newvalue := v.Interface()
  
  	if oldvalue != "hello" || newvalue != "world" {
  		t.Errorf("aliasing: old=%q new=%q, want hello, world", oldvalue, newvalue)
  	}
  }
  
  var V = ValueOf
  
  func EmptyInterfaceV(x interface{}) Value {
  	return ValueOf(&x).Elem()
  }
  
  func ReaderV(x io.Reader) Value {
  	return ValueOf(&x).Elem()
  }
  
  func ReadWriterV(x io.ReadWriter) Value {
  	return ValueOf(&x).Elem()
  }
  
  type Empty struct{}
  type MyStruct struct {
  	x int `some:"tag"`
  }
  type MyString string
  type MyBytes []byte
  type MyRunes []int32
  type MyFunc func()
  type MyByte byte
  
  var convertTests = []struct {
  	in  Value
  	out Value
  }{
  	// numbers
  	/*
  		Edit .+1,/\*\//-1>cat >/tmp/x.go && go run /tmp/x.go
  
  		package main
  
  		import "fmt"
  
  		var numbers = []string{
  			"int8", "uint8", "int16", "uint16",
  			"int32", "uint32", "int64", "uint64",
  			"int", "uint", "uintptr",
  			"float32", "float64",
  		}
  
  		func main() {
  			// all pairs but in an unusual order,
  			// to emit all the int8, uint8 cases
  			// before n grows too big.
  			n := 1
  			for i, f := range numbers {
  				for _, g := range numbers[i:] {
  					fmt.Printf("\t{V(%s(%d)), V(%s(%d))},\n", f, n, g, n)
  					n++
  					if f != g {
  						fmt.Printf("\t{V(%s(%d)), V(%s(%d))},\n", g, n, f, n)
  						n++
  					}
  				}
  			}
  		}
  	*/
  	{V(int8(1)), V(int8(1))},
  	{V(int8(2)), V(uint8(2))},
  	{V(uint8(3)), V(int8(3))},
  	{V(int8(4)), V(int16(4))},
  	{V(int16(5)), V(int8(5))},
  	{V(int8(6)), V(uint16(6))},
  	{V(uint16(7)), V(int8(7))},
  	{V(int8(8)), V(int32(8))},
  	{V(int32(9)), V(int8(9))},
  	{V(int8(10)), V(uint32(10))},
  	{V(uint32(11)), V(int8(11))},
  	{V(int8(12)), V(int64(12))},
  	{V(int64(13)), V(int8(13))},
  	{V(int8(14)), V(uint64(14))},
  	{V(uint64(15)), V(int8(15))},
  	{V(int8(16)), V(int(16))},
  	{V(int(17)), V(int8(17))},
  	{V(int8(18)), V(uint(18))},
  	{V(uint(19)), V(int8(19))},
  	{V(int8(20)), V(uintptr(20))},
  	{V(uintptr(21)), V(int8(21))},
  	{V(int8(22)), V(float32(22))},
  	{V(float32(23)), V(int8(23))},
  	{V(int8(24)), V(float64(24))},
  	{V(float64(25)), V(int8(25))},
  	{V(uint8(26)), V(uint8(26))},
  	{V(uint8(27)), V(int16(27))},
  	{V(int16(28)), V(uint8(28))},
  	{V(uint8(29)), V(uint16(29))},
  	{V(uint16(30)), V(uint8(30))},
  	{V(uint8(31)), V(int32(31))},
  	{V(int32(32)), V(uint8(32))},
  	{V(uint8(33)), V(uint32(33))},
  	{V(uint32(34)), V(uint8(34))},
  	{V(uint8(35)), V(int64(35))},
  	{V(int64(36)), V(uint8(36))},
  	{V(uint8(37)), V(uint64(37))},
  	{V(uint64(38)), V(uint8(38))},
  	{V(uint8(39)), V(int(39))},
  	{V(int(40)), V(uint8(40))},
  	{V(uint8(41)), V(uint(41))},
  	{V(uint(42)), V(uint8(42))},
  	{V(uint8(43)), V(uintptr(43))},
  	{V(uintptr(44)), V(uint8(44))},
  	{V(uint8(45)), V(float32(45))},
  	{V(float32(46)), V(uint8(46))},
  	{V(uint8(47)), V(float64(47))},
  	{V(float64(48)), V(uint8(48))},
  	{V(int16(49)), V(int16(49))},
  	{V(int16(50)), V(uint16(50))},
  	{V(uint16(51)), V(int16(51))},
  	{V(int16(52)), V(int32(52))},
  	{V(int32(53)), V(int16(53))},
  	{V(int16(54)), V(uint32(54))},
  	{V(uint32(55)), V(int16(55))},
  	{V(int16(56)), V(int64(56))},
  	{V(int64(57)), V(int16(57))},
  	{V(int16(58)), V(uint64(58))},
  	{V(uint64(59)), V(int16(59))},
  	{V(int16(60)), V(int(60))},
  	{V(int(61)), V(int16(61))},
  	{V(int16(62)), V(uint(62))},
  	{V(uint(63)), V(int16(63))},
  	{V(int16(64)), V(uintptr(64))},
  	{V(uintptr(65)), V(int16(65))},
  	{V(int16(66)), V(float32(66))},
  	{V(float32(67)), V(int16(67))},
  	{V(int16(68)), V(float64(68))},
  	{V(float64(69)), V(int16(69))},
  	{V(uint16(70)), V(uint16(70))},
  	{V(uint16(71)), V(int32(71))},
  	{V(int32(72)), V(uint16(72))},
  	{V(uint16(73)), V(uint32(73))},
  	{V(uint32(74)), V(uint16(74))},
  	{V(uint16(75)), V(int64(75))},
  	{V(int64(76)), V(uint16(76))},
  	{V(uint16(77)), V(uint64(77))},
  	{V(uint64(78)), V(uint16(78))},
  	{V(uint16(79)), V(int(79))},
  	{V(int(80)), V(uint16(80))},
  	{V(uint16(81)), V(uint(81))},
  	{V(uint(82)), V(uint16(82))},
  	{V(uint16(83)), V(uintptr(83))},
  	{V(uintptr(84)), V(uint16(84))},
  	{V(uint16(85)), V(float32(85))},
  	{V(float32(86)), V(uint16(86))},
  	{V(uint16(87)), V(float64(87))},
  	{V(float64(88)), V(uint16(88))},
  	{V(int32(89)), V(int32(89))},
  	{V(int32(90)), V(uint32(90))},
  	{V(uint32(91)), V(int32(91))},
  	{V(int32(92)), V(int64(92))},
  	{V(int64(93)), V(int32(93))},
  	{V(int32(94)), V(uint64(94))},
  	{V(uint64(95)), V(int32(95))},
  	{V(int32(96)), V(int(96))},
  	{V(int(97)), V(int32(97))},
  	{V(int32(98)), V(uint(98))},
  	{V(uint(99)), V(int32(99))},
  	{V(int32(100)), V(uintptr(100))},
  	{V(uintptr(101)), V(int32(101))},
  	{V(int32(102)), V(float32(102))},
  	{V(float32(103)), V(int32(103))},
  	{V(int32(104)), V(float64(104))},
  	{V(float64(105)), V(int32(105))},
  	{V(uint32(106)), V(uint32(106))},
  	{V(uint32(107)), V(int64(107))},
  	{V(int64(108)), V(uint32(108))},
  	{V(uint32(109)), V(uint64(109))},
  	{V(uint64(110)), V(uint32(110))},
  	{V(uint32(111)), V(int(111))},
  	{V(int(112)), V(uint32(112))},
  	{V(uint32(113)), V(uint(113))},
  	{V(uint(114)), V(uint32(114))},
  	{V(uint32(115)), V(uintptr(115))},
  	{V(uintptr(116)), V(uint32(116))},
  	{V(uint32(117)), V(float32(117))},
  	{V(float32(118)), V(uint32(118))},
  	{V(uint32(119)), V(float64(119))},
  	{V(float64(120)), V(uint32(120))},
  	{V(int64(121)), V(int64(121))},
  	{V(int64(122)), V(uint64(122))},
  	{V(uint64(123)), V(int64(123))},
  	{V(int64(124)), V(int(124))},
  	{V(int(125)), V(int64(125))},
  	{V(int64(126)), V(uint(126))},
  	{V(uint(127)), V(int64(127))},
  	{V(int64(128)), V(uintptr(128))},
  	{V(uintptr(129)), V(int64(129))},
  	{V(int64(130)), V(float32(130))},
  	{V(float32(131)), V(int64(131))},
  	{V(int64(132)), V(float64(132))},
  	{V(float64(133)), V(int64(133))},
  	{V(uint64(134)), V(uint64(134))},
  	{V(uint64(135)), V(int(135))},
  	{V(int(136)), V(uint64(136))},
  	{V(uint64(137)), V(uint(137))},
  	{V(uint(138)), V(uint64(138))},
  	{V(uint64(139)), V(uintptr(139))},
  	{V(uintptr(140)), V(uint64(140))},
  	{V(uint64(141)), V(float32(141))},
  	{V(float32(142)), V(uint64(142))},
  	{V(uint64(143)), V(float64(143))},
  	{V(float64(144)), V(uint64(144))},
  	{V(int(145)), V(int(145))},
  	{V(int(146)), V(uint(146))},
  	{V(uint(147)), V(int(147))},
  	{V(int(148)), V(uintptr(148))},
  	{V(uintptr(149)), V(int(149))},
  	{V(int(150)), V(float32(150))},
  	{V(float32(151)), V(int(151))},
  	{V(int(152)), V(float64(152))},
  	{V(float64(153)), V(int(153))},
  	{V(uint(154)), V(uint(154))},
  	{V(uint(155)), V(uintptr(155))},
  	{V(uintptr(156)), V(uint(156))},
  	{V(uint(157)), V(float32(157))},
  	{V(float32(158)), V(uint(158))},
  	{V(uint(159)), V(float64(159))},
  	{V(float64(160)), V(uint(160))},
  	{V(uintptr(161)), V(uintptr(161))},
  	{V(uintptr(162)), V(float32(162))},
  	{V(float32(163)), V(uintptr(163))},
  	{V(uintptr(164)), V(float64(164))},
  	{V(float64(165)), V(uintptr(165))},
  	{V(float32(166)), V(float32(166))},
  	{V(float32(167)), V(float64(167))},
  	{V(float64(168)), V(float32(168))},
  	{V(float64(169)), V(float64(169))},
  
  	// truncation
  	{V(float64(1.5)), V(int(1))},
  
  	// complex
  	{V(complex64(1i)), V(complex64(1i))},
  	{V(complex64(2i)), V(complex128(2i))},
  	{V(complex128(3i)), V(complex64(3i))},
  	{V(complex128(4i)), V(complex128(4i))},
  
  	// string
  	{V(string("hello")), V(string("hello"))},
  	{V(string("bytes1")), V([]byte("bytes1"))},
  	{V([]byte("bytes2")), V(string("bytes2"))},
  	{V([]byte("bytes3")), V([]byte("bytes3"))},
  	{V(string("runes♝")), V([]rune("runes♝"))},
  	{V([]rune("runes♕")), V(string("runes♕"))},
  	{V([]rune("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))},
  	{V(int('a')), V(string("a"))},
  	{V(int8('a')), V(string("a"))},
  	{V(int16('a')), V(string("a"))},
  	{V(int32('a')), V(string("a"))},
  	{V(int64('a')), V(string("a"))},
  	{V(uint('a')), V(string("a"))},
  	{V(uint8('a')), V(string("a"))},
  	{V(uint16('a')), V(string("a"))},
  	{V(uint32('a')), V(string("a"))},
  	{V(uint64('a')), V(string("a"))},
  	{V(uintptr('a')), V(string("a"))},
  	{V(int(-1)), V(string("\uFFFD"))},
  	{V(int8(-2)), V(string("\uFFFD"))},
  	{V(int16(-3)), V(string("\uFFFD"))},
  	{V(int32(-4)), V(string("\uFFFD"))},
  	{V(int64(-5)), V(string("\uFFFD"))},
  	{V(uint(0x110001)), V(string("\uFFFD"))},
  	{V(uint32(0x110002)), V(string("\uFFFD"))},
  	{V(uint64(0x110003)), V(string("\uFFFD"))},
  	{V(uintptr(0x110004)), V(string("\uFFFD"))},
  
  	// named string
  	{V(MyString("hello")), V(string("hello"))},
  	{V(string("hello")), V(MyString("hello"))},
  	{V(string("hello")), V(string("hello"))},
  	{V(MyString("hello")), V(MyString("hello"))},
  	{V(MyString("bytes1")), V([]byte("bytes1"))},
  	{V([]byte("bytes2")), V(MyString("bytes2"))},
  	{V([]byte("bytes3")), V([]byte("bytes3"))},
  	{V(MyString("runes♝")), V([]rune("runes♝"))},
  	{V([]rune("runes♕")), V(MyString("runes♕"))},
  	{V([]rune("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))},
  	{V([]rune("runes🙈🙉🙊")), V(MyRunes("runes🙈🙉🙊"))},
  	{V(MyRunes("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))},
  	{V(int('a')), V(MyString("a"))},
  	{V(int8('a')), V(MyString("a"))},
  	{V(int16('a')), V(MyString("a"))},
  	{V(int32('a')), V(MyString("a"))},
  	{V(int64('a')), V(MyString("a"))},
  	{V(uint('a')), V(MyString("a"))},
  	{V(uint8('a')), V(MyString("a"))},
  	{V(uint16('a')), V(MyString("a"))},
  	{V(uint32('a')), V(MyString("a"))},
  	{V(uint64('a')), V(MyString("a"))},
  	{V(uintptr('a')), V(MyString("a"))},
  	{V(int(-1)), V(MyString("\uFFFD"))},
  	{V(int8(-2)), V(MyString("\uFFFD"))},
  	{V(int16(-3)), V(MyString("\uFFFD"))},
  	{V(int32(-4)), V(MyString("\uFFFD"))},
  	{V(int64(-5)), V(MyString("\uFFFD"))},
  	{V(uint(0x110001)), V(MyString("\uFFFD"))},
  	{V(uint32(0x110002)), V(MyString("\uFFFD"))},
  	{V(uint64(0x110003)), V(MyString("\uFFFD"))},
  	{V(uintptr(0x110004)), V(MyString("\uFFFD"))},
  
  	// named []byte
  	{V(string("bytes1")), V(MyBytes("bytes1"))},
  	{V(MyBytes("bytes2")), V(string("bytes2"))},
  	{V(MyBytes("bytes3")), V(MyBytes("bytes3"))},
  	{V(MyString("bytes1")), V(MyBytes("bytes1"))},
  	{V(MyBytes("bytes2")), V(MyString("bytes2"))},
  
  	// named []rune
  	{V(string("runes♝")), V(MyRunes("runes♝"))},
  	{V(MyRunes("runes♕")), V(string("runes♕"))},
  	{V(MyRunes("runes🙈🙉🙊")), V(MyRunes("runes🙈🙉🙊"))},
  	{V(MyString("runes♝")), V(MyRunes("runes♝"))},
  	{V(MyRunes("runes♕")), V(MyString("runes♕"))},
  
  	// named types and equal underlying types
  	{V(new(int)), V(new(integer))},
  	{V(new(integer)), V(new(int))},
  	{V(Empty{}), V(struct{}{})},
  	{V(new(Empty)), V(new(struct{}))},
  	{V(struct{}{}), V(Empty{})},
  	{V(new(struct{})), V(new(Empty))},
  	{V(Empty{}), V(Empty{})},
  	{V(MyBytes{}), V([]byte{})},
  	{V([]byte{}), V(MyBytes{})},
  	{V((func())(nil)), V(MyFunc(nil))},
  	{V((MyFunc)(nil)), V((func())(nil))},
  
  	// structs with different tags
  	{V(struct {
  		x int `some:"foo"`
  	}{}), V(struct {
  		x int `some:"bar"`
  	}{})},
  
  	{V(struct {
  		x int `some:"bar"`
  	}{}), V(struct {
  		x int `some:"foo"`
  	}{})},
  
  	{V(MyStruct{}), V(struct {
  		x int `some:"foo"`
  	}{})},
  
  	{V(struct {
  		x int `some:"foo"`
  	}{}), V(MyStruct{})},
  
  	{V(MyStruct{}), V(struct {
  		x int `some:"bar"`
  	}{})},
  
  	{V(struct {
  		x int `some:"bar"`
  	}{}), V(MyStruct{})},
  
  	// can convert *byte and *MyByte
  	{V((*byte)(nil)), V((*MyByte)(nil))},
  	{V((*MyByte)(nil)), V((*byte)(nil))},
  
  	// cannot convert mismatched array sizes
  	{V([2]byte{}), V([2]byte{})},
  	{V([3]byte{}), V([3]byte{})},
  
  	// cannot convert other instances
  	{V((**byte)(nil)), V((**byte)(nil))},
  	{V((**MyByte)(nil)), V((**MyByte)(nil))},
  	{V((chan byte)(nil)), V((chan byte)(nil))},
  	{V((chan MyByte)(nil)), V((chan MyByte)(nil))},
  	{V(([]byte)(nil)), V(([]byte)(nil))},
  	{V(([]MyByte)(nil)), V(([]MyByte)(nil))},
  	{V((map[int]byte)(nil)), V((map[int]byte)(nil))},
  	{V((map[int]MyByte)(nil)), V((map[int]MyByte)(nil))},
  	{V((map[byte]int)(nil)), V((map[byte]int)(nil))},
  	{V((map[MyByte]int)(nil)), V((map[MyByte]int)(nil))},
  	{V([2]byte{}), V([2]byte{})},
  	{V([2]MyByte{}), V([2]MyByte{})},
  
  	// other
  	{V((***int)(nil)), V((***int)(nil))},
  	{V((***byte)(nil)), V((***byte)(nil))},
  	{V((***int32)(nil)), V((***int32)(nil))},
  	{V((***int64)(nil)), V((***int64)(nil))},
  	{V((chan int)(nil)), V((<-chan int)(nil))},
  	{V((chan int)(nil)), V((chan<- int)(nil))},
  	{V((chan string)(nil)), V((<-chan string)(nil))},
  	{V((chan string)(nil)), V((chan<- string)(nil))},
  	{V((chan byte)(nil)), V((chan byte)(nil))},
  	{V((chan MyByte)(nil)), V((chan MyByte)(nil))},
  	{V((map[int]bool)(nil)), V((map[int]bool)(nil))},
  	{V((map[int]byte)(nil)), V((map[int]byte)(nil))},
  	{V((map[uint]bool)(nil)), V((map[uint]bool)(nil))},
  	{V([]uint(nil)), V([]uint(nil))},
  	{V([]int(nil)), V([]int(nil))},
  	{V(new(interface{})), V(new(interface{}))},
  	{V(new(io.Reader)), V(new(io.Reader))},
  	{V(new(io.Writer)), V(new(io.Writer))},
  
  	// interfaces
  	{V(int(1)), EmptyInterfaceV(int(1))},
  	{V(string("hello")), EmptyInterfaceV(string("hello"))},
  	{V(new(bytes.Buffer)), ReaderV(new(bytes.Buffer))},
  	{ReadWriterV(new(bytes.Buffer)), ReaderV(new(bytes.Buffer))},
  	{V(new(bytes.Buffer)), ReadWriterV(new(bytes.Buffer))},
  }
  
  func TestConvert(t *testing.T) {
  	canConvert := map[[2]Type]bool{}
  	all := map[Type]bool{}
  
  	for _, tt := range convertTests {
  		t1 := tt.in.Type()
  		if !t1.ConvertibleTo(t1) {
  			t.Errorf("(%s).ConvertibleTo(%s) = false, want true", t1, t1)
  			continue
  		}
  
  		t2 := tt.out.Type()
  		if !t1.ConvertibleTo(t2) {
  			t.Errorf("(%s).ConvertibleTo(%s) = false, want true", t1, t2)
  			continue
  		}
  
  		all[t1] = true
  		all[t2] = true
  		canConvert[[2]Type{t1, t2}] = true
  
  		// vout1 represents the in value converted to the in type.
  		v1 := tt.in
  		vout1 := v1.Convert(t1)
  		out1 := vout1.Interface()
  		if vout1.Type() != tt.in.Type() || !DeepEqual(out1, tt.in.Interface()) {
  			t.Errorf("ValueOf(%T(%[1]v)).Convert(%s) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t1, out1, tt.in.Interface())
  		}
  
  		// vout2 represents the in value converted to the out type.
  		vout2 := v1.Convert(t2)
  		out2 := vout2.Interface()
  		if vout2.Type() != tt.out.Type() || !DeepEqual(out2, tt.out.Interface()) {
  			t.Errorf("ValueOf(%T(%[1]v)).Convert(%s) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t2, out2, tt.out.Interface())
  		}
  
  		// vout3 represents a new value of the out type, set to vout2.  This makes
  		// sure the converted value vout2 is really usable as a regular value.
  		vout3 := New(t2).Elem()
  		vout3.Set(vout2)
  		out3 := vout3.Interface()
  		if vout3.Type() != tt.out.Type() || !DeepEqual(out3, tt.out.Interface()) {
  			t.Errorf("Set(ValueOf(%T(%[1]v)).Convert(%s)) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t2, out3, tt.out.Interface())
  		}
  
  		if IsRO(v1) {
  			t.Errorf("table entry %v is RO, should not be", v1)
  		}
  		if IsRO(vout1) {
  			t.Errorf("self-conversion output %v is RO, should not be", vout1)
  		}
  		if IsRO(vout2) {
  			t.Errorf("conversion output %v is RO, should not be", vout2)
  		}
  		if IsRO(vout3) {
  			t.Errorf("set(conversion output) %v is RO, should not be", vout3)
  		}
  		if !IsRO(MakeRO(v1).Convert(t1)) {
  			t.Errorf("RO self-conversion output %v is not RO, should be", v1)
  		}
  		if !IsRO(MakeRO(v1).Convert(t2)) {
  			t.Errorf("RO conversion output %v is not RO, should be", v1)
  		}
  	}
  
  	// Assume that of all the types we saw during the tests,
  	// if there wasn't an explicit entry for a conversion between
  	// a pair of types, then it's not to be allowed. This checks for
  	// things like 'int64' converting to '*int'.
  	for t1 := range all {
  		for t2 := range all {
  			expectOK := t1 == t2 || canConvert[[2]Type{t1, t2}] || t2.Kind() == Interface && t2.NumMethod() == 0
  			if ok := t1.ConvertibleTo(t2); ok != expectOK {
  				t.Errorf("(%s).ConvertibleTo(%s) = %v, want %v", t1, t2, ok, expectOK)
  			}
  		}
  	}
  }
  
  type ComparableStruct struct {
  	X int
  }
  
  type NonComparableStruct struct {
  	X int
  	Y map[string]int
  }
  
  var comparableTests = []struct {
  	typ Type
  	ok  bool
  }{
  	{TypeOf(1), true},
  	{TypeOf("hello"), true},
  	{TypeOf(new(byte)), true},
  	{TypeOf((func())(nil)), false},
  	{TypeOf([]byte{}), false},
  	{TypeOf(map[string]int{}), false},
  	{TypeOf(make(chan int)), true},
  	{TypeOf(1.5), true},
  	{TypeOf(false), true},
  	{TypeOf(1i), true},
  	{TypeOf(ComparableStruct{}), true},
  	{TypeOf(NonComparableStruct{}), false},
  	{TypeOf([10]map[string]int{}), false},
  	{TypeOf([10]string{}), true},
  	{TypeOf(new(interface{})).Elem(), true},
  }
  
  func TestComparable(t *testing.T) {
  	for _, tt := range comparableTests {
  		if ok := tt.typ.Comparable(); ok != tt.ok {
  			t.Errorf("TypeOf(%v).Comparable() = %v, want %v", tt.typ, ok, tt.ok)
  		}
  	}
  }
  
  func TestOverflow(t *testing.T) {
  	if ovf := V(float64(0)).OverflowFloat(1e300); ovf {
  		t.Errorf("%v wrongly overflows float64", 1e300)
  	}
  
  	maxFloat32 := float64((1<<24 - 1) << (127 - 23))
  	if ovf := V(float32(0)).OverflowFloat(maxFloat32); ovf {
  		t.Errorf("%v wrongly overflows float32", maxFloat32)
  	}
  	ovfFloat32 := float64((1<<24-1)<<(127-23) + 1<<(127-52))
  	if ovf := V(float32(0)).OverflowFloat(ovfFloat32); !ovf {
  		t.Errorf("%v should overflow float32", ovfFloat32)
  	}
  	if ovf := V(float32(0)).OverflowFloat(-ovfFloat32); !ovf {
  		t.Errorf("%v should overflow float32", -ovfFloat32)
  	}
  
  	maxInt32 := int64(0x7fffffff)
  	if ovf := V(int32(0)).OverflowInt(maxInt32); ovf {
  		t.Errorf("%v wrongly overflows int32", maxInt32)
  	}
  	if ovf := V(int32(0)).OverflowInt(-1 << 31); ovf {
  		t.Errorf("%v wrongly overflows int32", -int64(1)<<31)
  	}
  	ovfInt32 := int64(1 << 31)
  	if ovf := V(int32(0)).OverflowInt(ovfInt32); !ovf {
  		t.Errorf("%v should overflow int32", ovfInt32)
  	}
  
  	maxUint32 := uint64(0xffffffff)
  	if ovf := V(uint32(0)).OverflowUint(maxUint32); ovf {
  		t.Errorf("%v wrongly overflows uint32", maxUint32)
  	}
  	ovfUint32 := uint64(1 << 32)
  	if ovf := V(uint32(0)).OverflowUint(ovfUint32); !ovf {
  		t.Errorf("%v should overflow uint32", ovfUint32)
  	}
  }
  
  func checkSameType(t *testing.T, x, y interface{}) {
  	if TypeOf(x) != TypeOf(y) {
  		t.Errorf("did not find preexisting type for %s (vs %s)", TypeOf(x), TypeOf(y))
  	}
  }
  
  func TestArrayOf(t *testing.T) {
  	// check construction and use of type not in binary
  	tests := []struct {
  		n          int
  		value      func(i int) interface{}
  		comparable bool
  		want       string
  	}{
  		{
  			n:          0,
  			value:      func(i int) interface{} { type Tint int; return Tint(i) },
  			comparable: true,
  			want:       "[]",
  		},
  		{
  			n:          10,
  			value:      func(i int) interface{} { type Tint int; return Tint(i) },
  			comparable: true,
  			want:       "[0 1 2 3 4 5 6 7 8 9]",
  		},
  		{
  			n:          10,
  			value:      func(i int) interface{} { type Tfloat float64; return Tfloat(i) },
  			comparable: true,
  			want:       "[0 1 2 3 4 5 6 7 8 9]",
  		},
  		{
  			n:          10,
  			value:      func(i int) interface{} { type Tstring string; return Tstring(strconv.Itoa(i)) },
  			comparable: true,
  			want:       "[0 1 2 3 4 5 6 7 8 9]",
  		},
  		{
  			n:          10,
  			value:      func(i int) interface{} { type Tstruct struct{ V int }; return Tstruct{i} },
  			comparable: true,
  			want:       "[{0} {1} {2} {3} {4} {5} {6} {7} {8} {9}]",
  		},
  		{
  			n:          10,
  			value:      func(i int) interface{} { type Tint int; return []Tint{Tint(i)} },
  			comparable: false,
  			want:       "[[0] [1] [2] [3] [4] [5] [6] [7] [8] [9]]",
  		},
  		{
  			n:          10,
  			value:      func(i int) interface{} { type Tint int; return [1]Tint{Tint(i)} },
  			comparable: true,
  			want:       "[[0] [1] [2] [3] [4] [5] [6] [7] [8] [9]]",
  		},
  		{
  			n:          10,
  			value:      func(i int) interface{} { type Tstruct struct{ V [1]int }; return Tstruct{[1]int{i}} },
  			comparable: true,
  			want:       "[{[0]} {[1]} {[2]} {[3]} {[4]} {[5]} {[6]} {[7]} {[8]} {[9]}]",
  		},
  		{
  			n:          10,
  			value:      func(i int) interface{} { type Tstruct struct{ V []int }; return Tstruct{[]int{i}} },
  			comparable: false,
  			want:       "[{[0]} {[1]} {[2]} {[3]} {[4]} {[5]} {[6]} {[7]} {[8]} {[9]}]",
  		},
  		{
  			n:          10,
  			value:      func(i int) interface{} { type TstructUV struct{ U, V int }; return TstructUV{i, i} },
  			comparable: true,
  			want:       "[{0 0} {1 1} {2 2} {3 3} {4 4} {5 5} {6 6} {7 7} {8 8} {9 9}]",
  		},
  		{
  			n: 10,
  			value: func(i int) interface{} {
  				type TstructUV struct {
  					U int
  					V float64
  				}
  				return TstructUV{i, float64(i)}
  			},
  			comparable: true,
  			want:       "[{0 0} {1 1} {2 2} {3 3} {4 4} {5 5} {6 6} {7 7} {8 8} {9 9}]",
  		},
  	}
  
  	for _, table := range tests {
  		at := ArrayOf(table.n, TypeOf(table.value(0)))
  		v := New(at).Elem()
  		vok := New(at).Elem()
  		vnot := New(at).Elem()
  		for i := 0; i < v.Len(); i++ {
  			v.Index(i).Set(ValueOf(table.value(i)))
  			vok.Index(i).Set(ValueOf(table.value(i)))
  			j := i
  			if i+1 == v.Len() {
  				j = i + 1
  			}
  			vnot.Index(i).Set(ValueOf(table.value(j))) // make it differ only by last element
  		}
  		s := fmt.Sprint(v.Interface())
  		if s != table.want {
  			t.Errorf("constructed array = %s, want %s", s, table.want)
  		}
  
  		if table.comparable != at.Comparable() {
  			t.Errorf("constructed array (%#v) is comparable=%v, want=%v", v.Interface(), at.Comparable(), table.comparable)
  		}
  		if table.comparable {
  			if table.n > 0 {
  				if DeepEqual(vnot.Interface(), v.Interface()) {
  					t.Errorf(
  						"arrays (%#v) compare ok (but should not)",
  						v.Interface(),
  					)
  				}
  			}
  			if !DeepEqual(vok.Interface(), v.Interface()) {
  				t.Errorf(
  					"arrays (%#v) compare NOT-ok (but should)",
  					v.Interface(),
  				)
  			}
  		}
  	}
  
  	// check that type already in binary is found
  	type T int
  	checkSameType(t, Zero(ArrayOf(5, TypeOf(T(1)))).Interface(), [5]T{})
  }
  
  func TestArrayOfGC(t *testing.T) {
  	type T *uintptr
  	tt := TypeOf(T(nil))
  	const n = 100
  	var x []interface{}
  	for i := 0; i < n; i++ {
  		v := New(ArrayOf(n, tt)).Elem()
  		for j := 0; j < v.Len(); j++ {
  			p := new(uintptr)
  			*p = uintptr(i*n + j)
  			v.Index(j).Set(ValueOf(p).Convert(tt))
  		}
  		x = append(x, v.Interface())
  	}
  	runtime.GC()
  
  	for i, xi := range x {
  		v := ValueOf(xi)
  		for j := 0; j < v.Len(); j++ {
  			k := v.Index(j).Elem().Interface()
  			if k != uintptr(i*n+j) {
  				t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
  			}
  		}
  	}
  }
  
  func TestArrayOfAlg(t *testing.T) {
  	at := ArrayOf(6, TypeOf(byte(0)))
  	v1 := New(at).Elem()
  	v2 := New(at).Elem()
  	if v1.Interface() != v1.Interface() {
  		t.Errorf("constructed array %v not equal to itself", v1.Interface())
  	}
  	v1.Index(5).Set(ValueOf(byte(1)))
  	if i1, i2 := v1.Interface(), v2.Interface(); i1 == i2 {
  		t.Errorf("constructed arrays %v and %v should not be equal", i1, i2)
  	}
  
  	at = ArrayOf(6, TypeOf([]int(nil)))
  	v1 = New(at).Elem()
  	shouldPanic(func() { _ = v1.Interface() == v1.Interface() })
  }
  
  func TestArrayOfGenericAlg(t *testing.T) {
  	at1 := ArrayOf(5, TypeOf(string("")))
  	at := ArrayOf(6, at1)
  	v1 := New(at).Elem()
  	v2 := New(at).Elem()
  	if v1.Interface() != v1.Interface() {
  		t.Errorf("constructed array %v not equal to itself", v1.Interface())
  	}
  
  	v1.Index(0).Index(0).Set(ValueOf("abc"))
  	v2.Index(0).Index(0).Set(ValueOf("efg"))
  	if i1, i2 := v1.Interface(), v2.Interface(); i1 == i2 {
  		t.Errorf("constructed arrays %v and %v should not be equal", i1, i2)
  	}
  
  	v1.Index(0).Index(0).Set(ValueOf("abc"))
  	v2.Index(0).Index(0).Set(ValueOf((v1.Index(0).Index(0).String() + " ")[:3]))
  	if i1, i2 := v1.Interface(), v2.Interface(); i1 != i2 {
  		t.Errorf("constructed arrays %v and %v should be equal", i1, i2)
  	}
  
  	// Test hash
  	m := MakeMap(MapOf(at, TypeOf(int(0))))
  	m.SetMapIndex(v1, ValueOf(1))
  	if i1, i2 := v1.Interface(), v2.Interface(); !m.MapIndex(v2).IsValid() {
  		t.Errorf("constructed arrays %v and %v have different hashes", i1, i2)
  	}
  }
  
  func TestArrayOfDirectIface(t *testing.T) {
  	{
  		type T [1]*byte
  		i1 := Zero(TypeOf(T{})).Interface()
  		v1 := ValueOf(&i1).Elem()
  		p1 := v1.InterfaceData()[1]
  
  		i2 := Zero(ArrayOf(1, PtrTo(TypeOf(int8(0))))).Interface()
  		v2 := ValueOf(&i2).Elem()
  		p2 := v2.InterfaceData()[1]
  
  		if p1 != 0 {
  			t.Errorf("got p1=%v. want=%v", p1, nil)
  		}
  
  		if p2 != 0 {
  			t.Errorf("got p2=%v. want=%v", p2, nil)
  		}
  	}
  	{
  		type T [0]*byte
  		i1 := Zero(TypeOf(T{})).Interface()
  		v1 := ValueOf(&i1).Elem()
  		p1 := v1.InterfaceData()[1]
  
  		i2 := Zero(ArrayOf(0, PtrTo(TypeOf(int8(0))))).Interface()
  		v2 := ValueOf(&i2).Elem()
  		p2 := v2.InterfaceData()[1]
  
  		if p1 == 0 {
  			t.Errorf("got p1=%v. want=not-%v", p1, nil)
  		}
  
  		if p2 == 0 {
  			t.Errorf("got p2=%v. want=not-%v", p2, nil)
  		}
  	}
  }
  
  func TestSliceOf(t *testing.T) {
  	// check construction and use of type not in binary
  	type T int
  	st := SliceOf(TypeOf(T(1)))
  	if got, want := st.String(), "[]reflect_test.T"; got != want {
  		t.Errorf("SliceOf(T(1)).String()=%q, want %q", got, want)
  	}
  	v := MakeSlice(st, 10, 10)
  	runtime.GC()
  	for i := 0; i < v.Len(); i++ {
  		v.Index(i).Set(ValueOf(T(i)))
  		runtime.GC()
  	}
  	s := fmt.Sprint(v.Interface())
  	want := "[0 1 2 3 4 5 6 7 8 9]"
  	if s != want {
  		t.Errorf("constructed slice = %s, want %s", s, want)
  	}
  
  	// check that type already in binary is found
  	type T1 int
  	checkSameType(t, Zero(SliceOf(TypeOf(T1(1)))).Interface(), []T1{})
  }
  
  func TestSliceOverflow(t *testing.T) {
  	// check that MakeSlice panics when size of slice overflows uint
  	const S = 1e6
  	s := uint(S)
  	l := (1<<(unsafe.Sizeof((*byte)(nil))*8)-1)/s + 1
  	if l*s >= s {
  		t.Fatal("slice size does not overflow")
  	}
  	var x [S]byte
  	st := SliceOf(TypeOf(x))
  	defer func() {
  		err := recover()
  		if err == nil {
  			t.Fatal("slice overflow does not panic")
  		}
  	}()
  	MakeSlice(st, int(l), int(l))
  }
  
  func TestSliceOfGC(t *testing.T) {
  	type T *uintptr
  	tt := TypeOf(T(nil))
  	st := SliceOf(tt)
  	const n = 100
  	var x []interface{}
  	for i := 0; i < n; i++ {
  		v := MakeSlice(st, n, n)
  		for j := 0; j < v.Len(); j++ {
  			p := new(uintptr)
  			*p = uintptr(i*n + j)
  			v.Index(j).Set(ValueOf(p).Convert(tt))
  		}
  		x = append(x, v.Interface())
  	}
  	runtime.GC()
  
  	for i, xi := range x {
  		v := ValueOf(xi)
  		for j := 0; j < v.Len(); j++ {
  			k := v.Index(j).Elem().Interface()
  			if k != uintptr(i*n+j) {
  				t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
  			}
  		}
  	}
  }
  
  func TestStructOfFieldName(t *testing.T) {
  	// invalid field name "1nvalid"
  	shouldPanic(func() {
  		StructOf([]StructField{
  			StructField{Name: "valid", Type: TypeOf("")},
  			StructField{Name: "1nvalid", Type: TypeOf("")},
  		})
  	})
  
  	// invalid field name "+"
  	shouldPanic(func() {
  		StructOf([]StructField{
  			StructField{Name: "val1d", Type: TypeOf("")},
  			StructField{Name: "+", Type: TypeOf("")},
  		})
  	})
  
  	// no field name
  	shouldPanic(func() {
  		StructOf([]StructField{
  			StructField{Name: "", Type: TypeOf("")},
  		})
  	})
  
  	// verify creation of a struct with valid struct fields
  	validFields := []StructField{
  		StructField{
  			Name: "φ",
  			Type: TypeOf(""),
  		},
  		StructField{
  			Name: "ValidName",
  			Type: TypeOf(""),
  		},
  		StructField{
  			Name: "Val1dNam5",
  			Type: TypeOf(""),
  		},
  	}
  
  	validStruct := StructOf(validFields)
  
  	const structStr = `struct { φ string; ValidName string; Val1dNam5 string }`
  	if got, want := validStruct.String(), structStr; got != want {
  		t.Errorf("StructOf(validFields).String()=%q, want %q", got, want)
  	}
  }
  
  func TestStructOf(t *testing.T) {
  	// check construction and use of type not in binary
  	fields := []StructField{
  		StructField{
  			Name: "S",
  			Tag:  "s",
  			Type: TypeOf(""),
  		},
  		StructField{
  			Name: "X",
  			Tag:  "x",
  			Type: TypeOf(byte(0)),
  		},
  		StructField{
  			Name: "Y",
  			Type: TypeOf(uint64(0)),
  		},
  		StructField{
  			Name: "Z",
  			Type: TypeOf([3]uint16{}),
  		},
  	}
  
  	st := StructOf(fields)
  	v := New(st).Elem()
  	runtime.GC()
  	v.FieldByName("X").Set(ValueOf(byte(2)))
  	v.FieldByIndex([]int{1}).Set(ValueOf(byte(1)))
  	runtime.GC()
  
  	s := fmt.Sprint(v.Interface())
  	want := `{ 1 0 [0 0 0]}`
  	if s != want {
  		t.Errorf("constructed struct = %s, want %s", s, want)
  	}
  	const stStr = `struct { S string "s"; X uint8 "x"; Y uint64; Z [3]uint16 }`
  	if got, want := st.String(), stStr; got != want {
  		t.Errorf("StructOf(fields).String()=%q, want %q", got, want)
  	}
  
  	// check the size, alignment and field offsets
  	stt := TypeOf(struct {
  		String string
  		X      byte
  		Y      uint64
  		Z      [3]uint16
  	}{})
  	if st.Size() != stt.Size() {
  		t.Errorf("constructed struct size = %v, want %v", st.Size(), stt.Size())
  	}
  	if st.Align() != stt.Align() {
  		t.Errorf("constructed struct align = %v, want %v", st.Align(), stt.Align())
  	}
  	if st.FieldAlign() != stt.FieldAlign() {
  		t.Errorf("constructed struct field align = %v, want %v", st.FieldAlign(), stt.FieldAlign())
  	}
  	for i := 0; i < st.NumField(); i++ {
  		o1 := st.Field(i).Offset
  		o2 := stt.Field(i).Offset
  		if o1 != o2 {
  			t.Errorf("constructed struct field %v offset = %v, want %v", i, o1, o2)
  		}
  	}
  
  	// Check size and alignment with a trailing zero-sized field.
  	st = StructOf([]StructField{
  		{
  			Name: "F1",
  			Type: TypeOf(byte(0)),
  		},
  		{
  			Name: "F2",
  			Type: TypeOf([0]*byte{}),
  		},
  	})
  	stt = TypeOf(struct {
  		G1 byte
  		G2 [0]*byte
  	}{})
  	if st.Size() != stt.Size() {
  		t.Errorf("constructed zero-padded struct size = %v, want %v", st.Size(), stt.Size())
  	}
  	if st.Align() != stt.Align() {
  		t.Errorf("constructed zero-padded struct align = %v, want %v", st.Align(), stt.Align())
  	}
  	if st.FieldAlign() != stt.FieldAlign() {
  		t.Errorf("constructed zero-padded struct field align = %v, want %v", st.FieldAlign(), stt.FieldAlign())
  	}
  	for i := 0; i < st.NumField(); i++ {
  		o1 := st.Field(i).Offset
  		o2 := stt.Field(i).Offset
  		if o1 != o2 {
  			t.Errorf("constructed zero-padded struct field %v offset = %v, want %v", i, o1, o2)
  		}
  	}
  
  	// check duplicate names
  	shouldPanic(func() {
  		StructOf([]StructField{
  			StructField{Name: "string", Type: TypeOf("")},
  			StructField{Name: "string", Type: TypeOf("")},
  		})
  	})
  	shouldPanic(func() {
  		StructOf([]StructField{
  			StructField{Type: TypeOf("")},
  			StructField{Name: "string", Type: TypeOf("")},
  		})
  	})
  	shouldPanic(func() {
  		StructOf([]StructField{
  			StructField{Type: TypeOf("")},
  			StructField{Type: TypeOf("")},
  		})
  	})
  	// check that type already in binary is found
  	checkSameType(t, Zero(StructOf(fields[2:3])).Interface(), struct{ Y uint64 }{})
  }
  
  func TestStructOfExportRules(t *testing.T) {
  	type S1 struct{}
  	type s2 struct{}
  	type ΦType struct{}
  	type φType struct{}
  
  	testPanic := func(i int, mustPanic bool, f func()) {
  		defer func() {
  			err := recover()
  			if err == nil && mustPanic {
  				t.Errorf("test-%d did not panic", i)
  			}
  			if err != nil && !mustPanic {
  				t.Errorf("test-%d panicked: %v\n", i, err)
  			}
  		}()
  		f()
  	}
  
  	tests := []struct {
  		field     StructField
  		mustPanic bool
  		exported  bool
  	}{
  		{
  			field:    StructField{Name: "S1", Anonymous: true, Type: TypeOf(S1{})},
  			exported: true,
  		},
  		{
  			field:    StructField{Name: "S1", Anonymous: true, Type: TypeOf((*S1)(nil))},
  			exported: true,
  		},
  		{
  			field:     StructField{Name: "s2", Anonymous: true, Type: TypeOf(s2{})},
  			mustPanic: true,
  		},
  		{
  			field:     StructField{Name: "s2", Anonymous: true, Type: TypeOf((*s2)(nil))},
  			mustPanic: true,
  		},
  		{
  			field:     StructField{Name: "Name", Type: nil, PkgPath: ""},
  			mustPanic: true,
  		},
  		{
  			field:     StructField{Name: "", Type: TypeOf(S1{}), PkgPath: ""},
  			mustPanic: true,
  		},
  		{
  			field:     StructField{Name: "S1", Anonymous: true, Type: TypeOf(S1{}), PkgPath: "other/pkg"},
  			mustPanic: true,
  		},
  		{
  			field:     StructField{Name: "S1", Anonymous: true, Type: TypeOf((*S1)(nil)), PkgPath: "other/pkg"},
  			mustPanic: true,
  		},
  		{
  			field:     StructField{Name: "s2", Anonymous: true, Type: TypeOf(s2{}), PkgPath: "other/pkg"},
  			mustPanic: true,
  		},
  		{
  			field:     StructField{Name: "s2", Anonymous: true, Type: TypeOf((*s2)(nil)), PkgPath: "other/pkg"},
  			mustPanic: true,
  		},
  		{
  			field:     StructField{Name: "s2", Type: TypeOf(int(0)), PkgPath: "other/pkg"},
  			mustPanic: true,
  		},
  		{
  			field:     StructField{Name: "s2", Type: TypeOf(int(0)), PkgPath: "other/pkg"},
  			mustPanic: true,
  		},
  		{
  			field:     StructField{Name: "S", Type: TypeOf(S1{})},
  			mustPanic: false,
  			exported:  true,
  		},
  		{
  			field:    StructField{Name: "S", Type: TypeOf((*S1)(nil))},
  			exported: true,
  		},
  		{
  			field:    StructField{Name: "S", Type: TypeOf(s2{})},
  			exported: true,
  		},
  		{
  			field:    StructField{Name: "S", Type: TypeOf((*s2)(nil))},
  			exported: true,
  		},
  		{
  			field:     StructField{Name: "s", Type: TypeOf(S1{})},
  			mustPanic: true,
  		},
  		{
  			field:     StructField{Name: "s", Type: TypeOf((*S1)(nil))},
  			mustPanic: true,
  		},
  		{
  			field:     StructField{Name: "s", Type: TypeOf(s2{})},
  			mustPanic: true,
  		},
  		{
  			field:     StructField{Name: "s", Type: TypeOf((*s2)(nil))},
  			mustPanic: true,
  		},
  		{
  			field:     StructField{Name: "s", Type: TypeOf(S1{}), PkgPath: "other/pkg"},
  			mustPanic: true, // TODO(sbinet): creating a name with a package path
  		},
  		{
  			field:     StructField{Name: "s", Type: TypeOf((*S1)(nil)), PkgPath: "other/pkg"},
  			mustPanic: true, // TODO(sbinet): creating a name with a package path
  		},
  		{
  			field:     StructField{Name: "s", Type: TypeOf(s2{}), PkgPath: "other/pkg"},
  			mustPanic: true, // TODO(sbinet): creating a name with a package path
  		},
  		{
  			field:     StructField{Name: "s", Type: TypeOf((*s2)(nil)), PkgPath: "other/pkg"},
  			mustPanic: true, // TODO(sbinet): creating a name with a package path
  		},
  		{
  			field:     StructField{Name: "", Type: TypeOf(ΦType{})},
  			mustPanic: true,
  		},
  		{
  			field:     StructField{Name: "", Type: TypeOf(φType{})},
  			mustPanic: true,
  		},
  		{
  			field:    StructField{Name: "Φ", Type: TypeOf(0)},
  			exported: true,
  		},
  		{
  			field:    StructField{Name: "φ", Type: TypeOf(0)},
  			exported: false,
  		},
  	}
  
  	for i, test := range tests {
  		testPanic(i, test.mustPanic, func() {
  			typ := StructOf([]StructField{test.field})
  			if typ == nil {
  				t.Errorf("test-%d: error creating struct type", i)
  				return
  			}
  			field := typ.Field(0)
  			n := field.Name
  			if n == "" {
  				panic("field.Name must not be empty")
  			}
  			exported := isExported(n)
  			if exported != test.exported {
  				t.Errorf("test-%d: got exported=%v want exported=%v", i, exported, test.exported)
  			}
  		})
  	}
  }
  
  // isExported reports whether name is an exported Go symbol
  // (that is, whether it begins with an upper-case letter).
  //
  func isExported(name string) bool {
  	ch, _ := utf8.DecodeRuneInString(name)
  	return unicode.IsUpper(ch)
  }
  
  func TestStructOfGC(t *testing.T) {
  	type T *uintptr
  	tt := TypeOf(T(nil))
  	fields := []StructField{
  		{Name: "X", Type: tt},
  		{Name: "Y", Type: tt},
  	}
  	st := StructOf(fields)
  
  	const n = 10000
  	var x []interface{}
  	for i := 0; i < n; i++ {
  		v := New(st).Elem()
  		for j := 0; j < v.NumField(); j++ {
  			p := new(uintptr)
  			*p = uintptr(i*n + j)
  			v.Field(j).Set(ValueOf(p).Convert(tt))
  		}
  		x = append(x, v.Interface())
  	}
  	runtime.GC()
  
  	for i, xi := range x {
  		v := ValueOf(xi)
  		for j := 0; j < v.NumField(); j++ {
  			k := v.Field(j).Elem().Interface()
  			if k != uintptr(i*n+j) {
  				t.Errorf("lost x[%d].%c = %d, want %d", i, "XY"[j], k, i*n+j)
  			}
  		}
  	}
  }
  
  func TestStructOfAlg(t *testing.T) {
  	st := StructOf([]StructField{{Name: "X", Tag: "x", Type: TypeOf(int(0))}})
  	v1 := New(st).Elem()
  	v2 := New(st).Elem()
  	if !DeepEqual(v1.Interface(), v1.Interface()) {
  		t.Errorf("constructed struct %v not equal to itself", v1.Interface())
  	}
  	v1.FieldByName("X").Set(ValueOf(int(1)))
  	if i1, i2 := v1.Interface(), v2.Interface(); DeepEqual(i1, i2) {
  		t.Errorf("constructed structs %v and %v should not be equal", i1, i2)
  	}
  
  	st = StructOf([]StructField{{Name: "X", Tag: "x", Type: TypeOf([]int(nil))}})
  	v1 = New(st).Elem()
  	shouldPanic(func() { _ = v1.Interface() == v1.Interface() })
  }
  
  func TestStructOfGenericAlg(t *testing.T) {
  	st1 := StructOf([]StructField{
  		{Name: "X", Tag: "x", Type: TypeOf(int64(0))},
  		{Name: "Y", Type: TypeOf(string(""))},
  	})
  	st := StructOf([]StructField{
  		{Name: "S0", Type: st1},
  		{Name: "S1", Type: st1},
  	})
  
  	tests := []struct {
  		rt  Type
  		idx []int
  	}{
  		{
  			rt:  st,
  			idx: []int{0, 1},
  		},
  		{
  			rt:  st1,
  			idx: []int{1},
  		},
  		{
  			rt: StructOf(
  				[]StructField{
  					{Name: "XX", Type: TypeOf([0]int{})},
  					{Name: "YY", Type: TypeOf("")},
  				},
  			),
  			idx: []int{1},
  		},
  		{
  			rt: StructOf(
  				[]StructField{
  					{Name: "XX", Type: TypeOf([0]int{})},
  					{Name: "YY", Type: TypeOf("")},
  					{Name: "ZZ", Type: TypeOf([2]int{})},
  				},
  			),
  			idx: []int{1},
  		},
  		{
  			rt: StructOf(
  				[]StructField{
  					{Name: "XX", Type: TypeOf([1]int{})},
  					{Name: "YY", Type: TypeOf("")},
  				},
  			),
  			idx: []int{1},
  		},
  		{
  			rt: StructOf(
  				[]StructField{
  					{Name: "XX", Type: TypeOf([1]int{})},
  					{Name: "YY", Type: TypeOf("")},
  					{Name: "ZZ", Type: TypeOf([1]int{})},
  				},
  			),
  			idx: []int{1},
  		},
  		{
  			rt: StructOf(
  				[]StructField{
  					{Name: "XX", Type: TypeOf([2]int{})},
  					{Name: "YY", Type: TypeOf("")},
  					{Name: "ZZ", Type: TypeOf([2]int{})},
  				},
  			),
  			idx: []int{1},
  		},
  		{
  			rt: StructOf(
  				[]StructField{
  					{Name: "XX", Type: TypeOf(int64(0))},
  					{Name: "YY", Type: TypeOf(byte(0))},
  					{Name: "ZZ", Type: TypeOf("")},
  				},
  			),
  			idx: []int{2},
  		},
  		{
  			rt: StructOf(
  				[]StructField{
  					{Name: "XX", Type: TypeOf(int64(0))},
  					{Name: "YY", Type: TypeOf(int64(0))},
  					{Name: "ZZ", Type: TypeOf("")},
  					{Name: "AA", Type: TypeOf([1]int64{})},
  				},
  			),
  			idx: []int{2},
  		},
  	}
  
  	for _, table := range tests {
  		v1 := New(table.rt).Elem()
  		v2 := New(table.rt).Elem()
  
  		if !DeepEqual(v1.Interface(), v1.Interface()) {
  			t.Errorf("constructed struct %v not equal to itself", v1.Interface())
  		}
  
  		v1.FieldByIndex(table.idx).Set(ValueOf("abc"))
  		v2.FieldByIndex(table.idx).Set(ValueOf("def"))
  		if i1, i2 := v1.Interface(), v2.Interface(); DeepEqual(i1, i2) {
  			t.Errorf("constructed structs %v and %v should not be equal", i1, i2)
  		}
  
  		abc := "abc"
  		v1.FieldByIndex(table.idx).Set(ValueOf(abc))
  		val := "+" + abc + "-"
  		v2.FieldByIndex(table.idx).Set(ValueOf(val[1:4]))
  		if i1, i2 := v1.Interface(), v2.Interface(); !DeepEqual(i1, i2) {
  			t.Errorf("constructed structs %v and %v should be equal", i1, i2)
  		}
  
  		// Test hash
  		m := MakeMap(MapOf(table.rt, TypeOf(int(0))))
  		m.SetMapIndex(v1, ValueOf(1))
  		if i1, i2 := v1.Interface(), v2.Interface(); !m.MapIndex(v2).IsValid() {
  			t.Errorf("constructed structs %#v and %#v have different hashes", i1, i2)
  		}
  
  		v2.FieldByIndex(table.idx).Set(ValueOf("abc"))
  		if i1, i2 := v1.Interface(), v2.Interface(); !DeepEqual(i1, i2) {
  			t.Errorf("constructed structs %v and %v should be equal", i1, i2)
  		}
  
  		if i1, i2 := v1.Interface(), v2.Interface(); !m.MapIndex(v2).IsValid() {
  			t.Errorf("constructed structs %v and %v have different hashes", i1, i2)
  		}
  	}
  }
  
  func TestStructOfDirectIface(t *testing.T) {
  	{
  		type T struct{ X [1]*byte }
  		i1 := Zero(TypeOf(T{})).Interface()
  		v1 := ValueOf(&i1).Elem()
  		p1 := v1.InterfaceData()[1]
  
  		i2 := Zero(StructOf([]StructField{
  			{
  				Name: "X",
  				Type: ArrayOf(1, TypeOf((*int8)(nil))),
  			},
  		})).Interface()
  		v2 := ValueOf(&i2).Elem()
  		p2 := v2.InterfaceData()[1]
  
  		if p1 != 0 {
  			t.Errorf("got p1=%v. want=%v", p1, nil)
  		}
  
  		if p2 != 0 {
  			t.Errorf("got p2=%v. want=%v", p2, nil)
  		}
  	}
  	{
  		type T struct{ X [0]*byte }
  		i1 := Zero(TypeOf(T{})).Interface()
  		v1 := ValueOf(&i1).Elem()
  		p1 := v1.InterfaceData()[1]
  
  		i2 := Zero(StructOf([]StructField{
  			{
  				Name: "X",
  				Type: ArrayOf(0, TypeOf((*int8)(nil))),
  			},
  		})).Interface()
  		v2 := ValueOf(&i2).Elem()
  		p2 := v2.InterfaceData()[1]
  
  		if p1 == 0 {
  			t.Errorf("got p1=%v. want=not-%v", p1, nil)
  		}
  
  		if p2 == 0 {
  			t.Errorf("got p2=%v. want=not-%v", p2, nil)
  		}
  	}
  }
  
  type StructI int
  
  func (i StructI) Get() int { return int(i) }
  
  type StructIPtr int
  
  func (i *StructIPtr) Get() int { return int(*i) }
  
  func TestStructOfWithInterface(t *testing.T) {
  	const want = 42
  	type Iface interface {
  		Get() int
  	}
  	tests := []struct {
  		name string
  		typ  Type
  		val  Value
  		impl bool
  	}{
  		{
  			name: "StructI",
  			typ:  TypeOf(StructI(want)),
  			val:  ValueOf(StructI(want)),
  			impl: true,
  		},
  		{
  			name: "StructI",
  			typ:  PtrTo(TypeOf(StructI(want))),
  			val: ValueOf(func() interface{} {
  				v := StructI(want)
  				return &v
  			}()),
  			impl: true,
  		},
  		{
  			name: "StructIPtr",
  			typ:  PtrTo(TypeOf(StructIPtr(want))),
  			val: ValueOf(func() interface{} {
  				v := StructIPtr(want)
  				return &v
  			}()),
  			impl: true,
  		},
  		{
  			name: "StructIPtr",
  			typ:  TypeOf(StructIPtr(want)),
  			val:  ValueOf(StructIPtr(want)),
  			impl: false,
  		},
  		// {
  		//	typ:  TypeOf((*Iface)(nil)).Elem(), // FIXME(sbinet): fix method.ifn/tfn
  		//	val:  ValueOf(StructI(want)),
  		//	impl: true,
  		// },
  	}
  
  	for i, table := range tests {
  		for j := 0; j < 2; j++ {
  			var fields []StructField
  			if j == 1 {
  				fields = append(fields, StructField{
  					Name:    "Dummy",
  					PkgPath: "",
  					Type:    TypeOf(int(0)),
  				})
  			}
  			fields = append(fields, StructField{
  				Name:      table.name,
  				Anonymous: true,
  				PkgPath:   "",
  				Type:      table.typ,
  			})
  
  			// We currently do not correctly implement methods
  			// for anonymous fields other than the first.
  			// Therefore, for now, we expect those methods
  			// to not exist.  See issues 15924 and 20824.
  			// When those issues are fixed, this test of panic
  			// should be removed.
  			if j == 1 && table.impl {
  				func() {
  					defer func() {
  						if err := recover(); err == nil {
  							t.Errorf("test-%d-%d did not panic", i, j)
  						}
  					}()
  					_ = StructOf(fields)
  				}()
  				continue
  			}
  
  			rt := StructOf(fields)
  			rv := New(rt).Elem()
  			rv.Field(j).Set(table.val)
  
  			if _, ok := rv.Interface().(Iface); ok != table.impl {
  				if table.impl {
  					t.Errorf("test-%d-%d: type=%v fails to implement Iface.\n", i, j, table.typ)
  				} else {
  					t.Errorf("test-%d-%d: type=%v should NOT implement Iface\n", i, j, table.typ)
  				}
  				continue
  			}
  
  			if !table.impl {
  				continue
  			}
  
  			v := rv.Interface().(Iface).Get()
  			if v != want {
  				t.Errorf("test-%d-%d: x.Get()=%v. want=%v\n", i, j, v, want)
  			}
  
  			fct := rv.MethodByName("Get")
  			out := fct.Call(nil)
  			if !DeepEqual(out[0].Interface(), want) {
  				t.Errorf("test-%d-%d: x.Get()=%v. want=%v\n", i, j, out[0].Interface(), want)
  			}
  		}
  	}
  }
  
  func TestChanOf(t *testing.T) {
  	// check construction and use of type not in binary
  	type T string
  	ct := ChanOf(BothDir, TypeOf(T("")))
  	v := MakeChan(ct, 2)
  	runtime.GC()
  	v.Send(ValueOf(T("hello")))
  	runtime.GC()
  	v.Send(ValueOf(T("world")))
  	runtime.GC()
  
  	sv1, _ := v.Recv()
  	sv2, _ := v.Recv()
  	s1 := sv1.String()
  	s2 := sv2.String()
  	if s1 != "hello" || s2 != "world" {
  		t.Errorf("constructed chan: have %q, %q, want %q, %q", s1, s2, "hello", "world")
  	}
  
  	// check that type already in binary is found
  	type T1 int
  	checkSameType(t, Zero(ChanOf(BothDir, TypeOf(T1(1)))).Interface(), (chan T1)(nil))
  }
  
  func TestChanOfDir(t *testing.T) {
  	// check construction and use of type not in binary
  	type T string
  	crt := ChanOf(RecvDir, TypeOf(T("")))
  	cst := ChanOf(SendDir, TypeOf(T("")))
  
  	// check that type already in binary is found
  	type T1 int
  	checkSameType(t, Zero(ChanOf(RecvDir, TypeOf(T1(1)))).Interface(), (<-chan T1)(nil))
  	checkSameType(t, Zero(ChanOf(SendDir, TypeOf(T1(1)))).Interface(), (chan<- T1)(nil))
  
  	// check String form of ChanDir
  	if crt.ChanDir().String() != "<-chan" {
  		t.Errorf("chan dir: have %q, want %q", crt.ChanDir().String(), "<-chan")
  	}
  	if cst.ChanDir().String() != "chan<-" {
  		t.Errorf("chan dir: have %q, want %q", cst.ChanDir().String(), "chan<-")
  	}
  }
  
  func TestChanOfGC(t *testing.T) {
  	done := make(chan bool, 1)
  	go func() {
  		select {
  		case <-done:
  		case <-time.After(5 * time.Second):
  			panic("deadlock in TestChanOfGC")
  		}
  	}()
  
  	defer func() {
  		done <- true
  	}()
  
  	type T *uintptr
  	tt := TypeOf(T(nil))
  	ct := ChanOf(BothDir, tt)
  
  	// NOTE: The garbage collector handles allocated channels specially,
  	// so we have to save pointers to channels in x; the pointer code will
  	// use the gc info in the newly constructed chan type.
  	const n = 100
  	var x []interface{}
  	for i := 0; i < n; i++ {
  		v := MakeChan(ct, n)
  		for j := 0; j < n; j++ {
  			p := new(uintptr)
  			*p = uintptr(i*n + j)
  			v.Send(ValueOf(p).Convert(tt))
  		}
  		pv := New(ct)
  		pv.Elem().Set(v)
  		x = append(x, pv.Interface())
  	}
  	runtime.GC()
  
  	for i, xi := range x {
  		v := ValueOf(xi).Elem()
  		for j := 0; j < n; j++ {
  			pv, _ := v.Recv()
  			k := pv.Elem().Interface()
  			if k != uintptr(i*n+j) {
  				t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
  			}
  		}
  	}
  }
  
  func TestMapOf(t *testing.T) {
  	// check construction and use of type not in binary
  	type K string
  	type V float64
  
  	v := MakeMap(MapOf(TypeOf(K("")), TypeOf(V(0))))
  	runtime.GC()
  	v.SetMapIndex(ValueOf(K("a")), ValueOf(V(1)))
  	runtime.GC()
  
  	s := fmt.Sprint(v.Interface())
  	want := "map[a:1]"
  	if s != want {
  		t.Errorf("constructed map = %s, want %s", s, want)
  	}
  
  	// check that type already in binary is found
  	checkSameType(t, Zero(MapOf(TypeOf(V(0)), TypeOf(K("")))).Interface(), map[V]K(nil))
  
  	// check that invalid key type panics
  	shouldPanic(func() { MapOf(TypeOf((func())(nil)), TypeOf(false)) })
  }
  
  func TestMapOfGCKeys(t *testing.T) {
  	type T *uintptr
  	tt := TypeOf(T(nil))
  	mt := MapOf(tt, TypeOf(false))
  
  	// NOTE: The garbage collector handles allocated maps specially,
  	// so we have to save pointers to maps in x; the pointer code will
  	// use the gc info in the newly constructed map type.
  	const n = 100
  	var x []interface{}
  	for i := 0; i < n; i++ {
  		v := MakeMap(mt)
  		for j := 0; j < n; j++ {
  			p := new(uintptr)
  			*p = uintptr(i*n + j)
  			v.SetMapIndex(ValueOf(p).Convert(tt), ValueOf(true))
  		}
  		pv := New(mt)
  		pv.Elem().Set(v)
  		x = append(x, pv.Interface())
  	}
  	runtime.GC()
  
  	for i, xi := range x {
  		v := ValueOf(xi).Elem()
  		var out []int
  		for _, kv := range v.MapKeys() {
  			out = append(out, int(kv.Elem().Interface().(uintptr)))
  		}
  		sort.Ints(out)
  		for j, k := range out {
  			if k != i*n+j {
  				t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
  			}
  		}
  	}
  }
  
  func TestMapOfGCValues(t *testing.T) {
  	type T *uintptr
  	tt := TypeOf(T(nil))
  	mt := MapOf(TypeOf(1), tt)
  
  	// NOTE: The garbage collector handles allocated maps specially,
  	// so we have to save pointers to maps in x; the pointer code will
  	// use the gc info in the newly constructed map type.
  	const n = 100
  	var x []interface{}
  	for i := 0; i < n; i++ {
  		v := MakeMap(mt)
  		for j := 0; j < n; j++ {
  			p := new(uintptr)
  			*p = uintptr(i*n + j)
  			v.SetMapIndex(ValueOf(j), ValueOf(p).Convert(tt))
  		}
  		pv := New(mt)
  		pv.Elem().Set(v)
  		x = append(x, pv.Interface())
  	}
  	runtime.GC()
  
  	for i, xi := range x {
  		v := ValueOf(xi).Elem()
  		for j := 0; j < n; j++ {
  			k := v.MapIndex(ValueOf(j)).Elem().Interface().(uintptr)
  			if k != uintptr(i*n+j) {
  				t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
  			}
  		}
  	}
  }
  
  func TestTypelinksSorted(t *testing.T) {
  	var last string
  	for i, n := range TypeLinks() {
  		if n < last {
  			t.Errorf("typelinks not sorted: %q [%d] > %q [%d]", last, i-1, n, i)
  		}
  		last = n
  	}
  }
  
  func TestFuncOf(t *testing.T) {
  	// check construction and use of type not in binary
  	type K string
  	type V float64
  
  	fn := func(args []Value) []Value {
  		if len(args) != 1 {
  			t.Errorf("args == %v, want exactly one arg", args)
  		} else if args[0].Type() != TypeOf(K("")) {
  			t.Errorf("args[0] is type %v, want %v", args[0].Type(), TypeOf(K("")))
  		} else if args[0].String() != "gopher" {
  			t.Errorf("args[0] = %q, want %q", args[0].String(), "gopher")
  		}
  		return []Value{ValueOf(V(3.14))}
  	}
  	v := MakeFunc(FuncOf([]Type{TypeOf(K(""))}, []Type{TypeOf(V(0))}, false), fn)
  
  	outs := v.Call([]Value{ValueOf(K("gopher"))})
  	if len(outs) != 1 {
  		t.Fatalf("v.Call returned %v, want exactly one result", outs)
  	} else if outs[0].Type() != TypeOf(V(0)) {
  		t.Fatalf("c.Call[0] is type %v, want %v", outs[0].Type(), TypeOf(V(0)))
  	}
  	f := outs[0].Float()
  	if f != 3.14 {
  		t.Errorf("constructed func returned %f, want %f", f, 3.14)
  	}
  
  	// check that types already in binary are found
  	type T1 int
  	testCases := []struct {
  		in, out  []Type
  		variadic bool
  		want     interface{}
  	}{
  		{in: []Type{TypeOf(T1(0))}, want: (func(T1))(nil)},
  		{in: []Type{TypeOf(int(0))}, want: (func(int))(nil)},
  		{in: []Type{SliceOf(TypeOf(int(0)))}, variadic: true, want: (func(...int))(nil)},
  		{in: []Type{TypeOf(int(0))}, out: []Type{TypeOf(false)}, want: (func(int) bool)(nil)},
  		{in: []Type{TypeOf(int(0))}, out: []Type{TypeOf(false), TypeOf("")}, want: (func(int) (bool, string))(nil)},
  	}
  	for _, tt := range testCases {
  		checkSameType(t, Zero(FuncOf(tt.in, tt.out, tt.variadic)).Interface(), tt.want)
  	}
  
  	// check that variadic requires last element be a slice.
  	FuncOf([]Type{TypeOf(1), TypeOf(""), SliceOf(TypeOf(false))}, nil, true)
  	shouldPanic(func() { FuncOf([]Type{TypeOf(0), TypeOf(""), TypeOf(false)}, nil, true) })
  	shouldPanic(func() { FuncOf(nil, nil, true) })
  }
  
  type B1 struct {
  	X int
  	Y int
  	Z int
  }
  
  func BenchmarkFieldByName1(b *testing.B) {
  	t := TypeOf(B1{})
  	b.RunParallel(func(pb *testing.PB) {
  		for pb.Next() {
  			t.FieldByName("Z")
  		}
  	})
  }
  
  func BenchmarkFieldByName2(b *testing.B) {
  	t := TypeOf(S3{})
  	b.RunParallel(func(pb *testing.PB) {
  		for pb.Next() {
  			t.FieldByName("B")
  		}
  	})
  }
  
  type R0 struct {
  	*R1
  	*R2
  	*R3
  	*R4
  }
  
  type R1 struct {
  	*R5
  	*R6
  	*R7
  	*R8
  }
  
  type R2 R1
  type R3 R1
  type R4 R1
  
  type R5 struct {
  	*R9
  	*R10
  	*R11
  	*R12
  }
  
  type R6 R5
  type R7 R5
  type R8 R5
  
  type R9 struct {
  	*R13
  	*R14
  	*R15
  	*R16
  }
  
  type R10 R9
  type R11 R9
  type R12 R9
  
  type R13 struct {
  	*R17
  	*R18
  	*R19
  	*R20
  }
  
  type R14 R13
  type R15 R13
  type R16 R13
  
  type R17 struct {
  	*R21
  	*R22
  	*R23
  	*R24
  }
  
  type R18 R17
  type R19 R17
  type R20 R17
  
  type R21 struct {
  	X int
  }
  
  type R22 R21
  type R23 R21
  type R24 R21
  
  func TestEmbed(t *testing.T) {
  	typ := TypeOf(R0{})
  	f, ok := typ.FieldByName("X")
  	if ok {
  		t.Fatalf(`FieldByName("X") should fail, returned %v`, f.Index)
  	}
  }
  
  func BenchmarkFieldByName3(b *testing.B) {
  	t := TypeOf(R0{})
  	b.RunParallel(func(pb *testing.PB) {
  		for pb.Next() {
  			t.FieldByName("X")
  		}
  	})
  }
  
  type S struct {
  	i1 int64
  	i2 int64
  }
  
  func BenchmarkInterfaceBig(b *testing.B) {
  	v := ValueOf(S{})
  	b.RunParallel(func(pb *testing.PB) {
  		for pb.Next() {
  			v.Interface()
  		}
  	})
  	b.StopTimer()
  }
  
  func TestAllocsInterfaceBig(t *testing.T) {
  	if testing.Short() {
  		t.Skip("skipping malloc count in short mode")
  	}
  	v := ValueOf(S{})
  	if allocs := testing.AllocsPerRun(100, func() { v.Interface() }); allocs > 0 {
  		t.Error("allocs:", allocs)
  	}
  }
  
  func BenchmarkInterfaceSmall(b *testing.B) {
  	v := ValueOf(int64(0))
  	b.RunParallel(func(pb *testing.PB) {
  		for pb.Next() {
  			v.Interface()
  		}
  	})
  }
  
  func TestAllocsInterfaceSmall(t *testing.T) {
  	if testing.Short() {
  		t.Skip("skipping malloc count in short mode")
  	}
  	v := ValueOf(int64(0))
  	if allocs := testing.AllocsPerRun(100, func() { v.Interface() }); allocs > 0 {
  		t.Error("allocs:", allocs)
  	}
  }
  
  // An exhaustive is a mechanism for writing exhaustive or stochastic tests.
  // The basic usage is:
  //
  //	for x.Next() {
  //		... code using x.Maybe() or x.Choice(n) to create test cases ...
  //	}
  //
  // Each iteration of the loop returns a different set of results, until all
  // possible result sets have been explored. It is okay for different code paths
  // to make different method call sequences on x, but there must be no
  // other source of non-determinism in the call sequences.
  //
  // When faced with a new decision, x chooses randomly. Future explorations
  // of that path will choose successive values for the result. Thus, stopping
  // the loop after a fixed number of iterations gives somewhat stochastic
  // testing.
  //
  // Example:
  //
  //	for x.Next() {
  //		v := make([]bool, x.Choose(4))
  //		for i := range v {
  //			v[i] = x.Maybe()
  //		}
  //		fmt.Println(v)
  //	}
  //
  // prints (in some order):
  //
  //	[]
  //	[false]
  //	[true]
  //	[false false]
  //	[false true]
  //	...
  //	[true true]
  //	[false false false]
  //	...
  //	[true true true]
  //	[false false false false]
  //	...
  //	[true true true true]
  //
  type exhaustive struct {
  	r    *rand.Rand
  	pos  int
  	last []choice
  }
  
  type choice struct {
  	off int
  	n   int
  	max int
  }
  
  func (x *exhaustive) Next() bool {
  	if x.r == nil {
  		x.r = rand.New(rand.NewSource(time.Now().UnixNano()))
  	}
  	x.pos = 0
  	if x.last == nil {
  		x.last = []choice{}
  		return true
  	}
  	for i := len(x.last) - 1; i >= 0; i-- {
  		c := &x.last[i]
  		if c.n+1 < c.max {
  			c.n++
  			x.last = x.last[:i+1]
  			return true
  		}
  	}
  	return false
  }
  
  func (x *exhaustive) Choose(max int) int {
  	if x.pos >= len(x.last) {
  		x.last = append(x.last, choice{x.r.Intn(max), 0, max})
  	}
  	c := &x.last[x.pos]
  	x.pos++
  	if c.max != max {
  		panic("inconsistent use of exhaustive tester")
  	}
  	return (c.n + c.off) % max
  }
  
  func (x *exhaustive) Maybe() bool {
  	return x.Choose(2) == 1
  }
  
  func GCFunc(args []Value) []Value {
  	runtime.GC()
  	return []Value{}
  }
  
  func TestReflectFuncTraceback(t *testing.T) {
  	f := MakeFunc(TypeOf(func() {}), GCFunc)
  	f.Call([]Value{})
  }
  
  func TestReflectMethodTraceback(t *testing.T) {
  	p := Point{3, 4}
  	m := ValueOf(p).MethodByName("GCMethod")
  	i := ValueOf(m.Interface()).Call([]Value{ValueOf(5)})[0].Int()
  	if i != 8 {
  		t.Errorf("Call returned %d; want 8", i)
  	}
  }
  
  func TestBigZero(t *testing.T) {
  	const size = 1 << 10
  	var v [size]byte
  	z := Zero(ValueOf(v).Type()).Interface().([size]byte)
  	for i := 0; i < size; i++ {
  		if z[i] != 0 {
  			t.Fatalf("Zero object not all zero, index %d", i)
  		}
  	}
  }
  
  func TestFieldByIndexNil(t *testing.T) {
  	type P struct {
  		F int
  	}
  	type T struct {
  		*P
  	}
  	v := ValueOf(T{})
  
  	v.FieldByName("P") // should be fine
  
  	defer func() {
  		if err := recover(); err == nil {
  			t.Fatalf("no error")
  		} else if !strings.Contains(fmt.Sprint(err), "nil pointer to embedded struct") {
  			t.Fatalf(`err=%q, wanted error containing "nil pointer to embedded struct"`, err)
  		}
  	}()
  	v.FieldByName("F") // should panic
  
  	t.Fatalf("did not panic")
  }
  
  // Given
  //	type Outer struct {
  //		*Inner
  //		...
  //	}
  // the compiler generates the implementation of (*Outer).M dispatching to the embedded Inner.
  // The implementation is logically:
  //	func (p *Outer) M() {
  //		(p.Inner).M()
  //	}
  // but since the only change here is the replacement of one pointer receiver with another,
  // the actual generated code overwrites the original receiver with the p.Inner pointer and
  // then jumps to the M method expecting the *Inner receiver.
  //
  // During reflect.Value.Call, we create an argument frame and the associated data structures
  // to describe it to the garbage collector, populate the frame, call reflect.call to
  // run a function call using that frame, and then copy the results back out of the frame.
  // The reflect.call function does a memmove of the frame structure onto the
  // stack (to set up the inputs), runs the call, and the memmoves the stack back to
  // the frame structure (to preserve the outputs).
  //
  // Originally reflect.call did not distinguish inputs from outputs: both memmoves
  // were for the full stack frame. However, in the case where the called function was
  // one of these wrappers, the rewritten receiver is almost certainly a different type
  // than the original receiver. This is not a problem on the stack, where we use the
  // program counter to determine the type information and understand that
  // during (*Outer).M the receiver is an *Outer while during (*Inner).M the receiver in the same
  // memory word is now an *Inner. But in the statically typed argument frame created
  // by reflect, the receiver is always an *Outer. Copying the modified receiver pointer
  // off the stack into the frame will store an *Inner there, and then if a garbage collection
  // happens to scan that argument frame before it is discarded, it will scan the *Inner
  // memory as if it were an *Outer. If the two have different memory layouts, the
  // collection will interpret the memory incorrectly.
  //
  // One such possible incorrect interpretation is to treat two arbitrary memory words
  // (Inner.P1 and Inner.P2 below) as an interface (Outer.R below). Because interpreting
  // an interface requires dereferencing the itab word, the misinterpretation will try to
  // deference Inner.P1, causing a crash during garbage collection.
  //
  // This came up in a real program in issue 7725.
  
  type Outer struct {
  	*Inner
  	R io.Reader
  }
  
  type Inner struct {
  	X  *Outer
  	P1 uintptr
  	P2 uintptr
  }
  
  func (pi *Inner) M() {
  	// Clear references to pi so that the only way the
  	// garbage collection will find the pointer is in the
  	// argument frame, typed as a *Outer.
  	pi.X.Inner = nil
  
  	// Set up an interface value that will cause a crash.
  	// P1 = 1 is a non-zero, so the interface looks non-nil.
  	// P2 = pi ensures that the data word points into the
  	// allocated heap; if not the collection skips the interface
  	// value as irrelevant, without dereferencing P1.
  	pi.P1 = 1
  	pi.P2 = uintptr(unsafe.Pointer(pi))
  }
  
  func TestCallMethodJump(t *testing.T) {
  	// In reflect.Value.Call, trigger a garbage collection after reflect.call
  	// returns but before the args frame has been discarded.
  	// This is a little clumsy but makes the failure repeatable.
  	*CallGC = true
  
  	p := &Outer{Inner: new(Inner)}
  	p.Inner.X = p
  	ValueOf(p).Method(0).Call(nil)
  
  	// Stop garbage collecting during reflect.call.
  	*CallGC = false
  }
  
  func TestMakeFuncStackCopy(t *testing.T) {
  	target := func(in []Value) []Value {
  		runtime.GC()
  		useStack(16)
  		return []Value{ValueOf(9)}
  	}
  
  	var concrete func(*int, int) int
  	fn := MakeFunc(ValueOf(concrete).Type(), target)
  	ValueOf(&concrete).Elem().Set(fn)
  	x := concrete(nil, 7)
  	if x != 9 {
  		t.Errorf("have %#q want 9", x)
  	}
  }
  
  // use about n KB of stack
  func useStack(n int) {
  	if n == 0 {
  		return
  	}
  	var b [1024]byte // makes frame about 1KB
  	useStack(n - 1 + int(b[99]))
  }
  
  type Impl struct{}
  
  func (Impl) F() {}
  
  func TestValueString(t *testing.T) {
  	rv := ValueOf(Impl{})
  	if rv.String() != "<reflect_test.Impl Value>" {
  		t.Errorf("ValueOf(Impl{}).String() = %q, want %q", rv.String(), "<reflect_test.Impl Value>")
  	}
  
  	method := rv.Method(0)
  	if method.String() != "<func() Value>" {
  		t.Errorf("ValueOf(Impl{}).Method(0).String() = %q, want %q", method.String(), "<func() Value>")
  	}
  }
  
  func TestInvalid(t *testing.T) {
  	// Used to have inconsistency between IsValid() and Kind() != Invalid.
  	type T struct{ v interface{} }
  
  	v := ValueOf(T{}).Field(0)
  	if v.IsValid() != true || v.Kind() != Interface {
  		t.Errorf("field: IsValid=%v, Kind=%v, want true, Interface", v.IsValid(), v.Kind())
  	}
  	v = v.Elem()
  	if v.IsValid() != false || v.Kind() != Invalid {
  		t.Errorf("field elem: IsValid=%v, Kind=%v, want false, Invalid", v.IsValid(), v.Kind())
  	}
  }
  
  // Issue 8917.
  func TestLargeGCProg(t *testing.T) {
  	fv := ValueOf(func([256]*byte) {})
  	fv.Call([]Value{ValueOf([256]*byte{})})
  }
  
  func fieldIndexRecover(t Type, i int) (recovered interface{}) {
  	defer func() {
  		recovered = recover()
  	}()
  
  	t.Field(i)
  	return
  }
  
  // Issue 15046.
  func TestTypeFieldOutOfRangePanic(t *testing.T) {
  	typ := TypeOf(struct{ X int }{10})
  	testIndices := [...]struct {
  		i         int
  		mustPanic bool
  	}{
  		0: {-2, true},
  		1: {0, false},
  		2: {1, true},
  		3: {1 << 10, true},
  	}
  	for i, tt := range testIndices {
  		recoveredErr := fieldIndexRecover(typ, tt.i)
  		if tt.mustPanic {
  			if recoveredErr == nil {
  				t.Errorf("#%d: fieldIndex %d expected to panic", i, tt.i)
  			}
  		} else {
  			if recoveredErr != nil {
  				t.Errorf("#%d: got err=%v, expected no panic", i, recoveredErr)
  			}
  		}
  	}
  }
  
  // Issue 9179.
  func TestCallGC(t *testing.T) {
  	f := func(a, b, c, d, e string) {
  	}
  	g := func(in []Value) []Value {
  		runtime.GC()
  		return nil
  	}
  	typ := ValueOf(f).Type()
  	f2 := MakeFunc(typ, g).Interface().(func(string, string, string, string, string))
  	f2("four", "five5", "six666", "seven77", "eight888")
  }
  
  // Issue 18635 (function version).
  func TestKeepFuncLive(t *testing.T) {
  	// Test that we keep makeFuncImpl live as long as it is
  	// referenced on the stack.
  	typ := TypeOf(func(i int) {})
  	var f, g func(in []Value) []Value
  	f = func(in []Value) []Value {
  		clobber()
  		i := int(in[0].Int())
  		if i > 0 {
  			// We can't use Value.Call here because
  			// runtime.call* will keep the makeFuncImpl
  			// alive. However, by converting it to an
  			// interface value and calling that,
  			// reflect.callReflect is the only thing that
  			// can keep the makeFuncImpl live.
  			//
  			// Alternate between f and g so that if we do
  			// reuse the memory prematurely it's more
  			// likely to get obviously corrupted.
  			MakeFunc(typ, g).Interface().(func(i int))(i - 1)
  		}
  		return nil
  	}
  	g = func(in []Value) []Value {
  		clobber()
  		i := int(in[0].Int())
  		MakeFunc(typ, f).Interface().(func(i int))(i)
  		return nil
  	}
  	MakeFunc(typ, f).Call([]Value{ValueOf(10)})
  }
  
  // Issue 18635 (method version).
  type KeepMethodLive struct{}
  
  func (k KeepMethodLive) Method1(i int) {
  	clobber()
  	if i > 0 {
  		ValueOf(k).MethodByName("Method2").Interface().(func(i int))(i - 1)
  	}
  }
  
  func (k KeepMethodLive) Method2(i int) {
  	clobber()
  	ValueOf(k).MethodByName("Method1").Interface().(func(i int))(i)
  }
  
  func TestKeepMethodLive(t *testing.T) {
  	// Test that we keep methodValue live as long as it is
  	// referenced on the stack.
  	KeepMethodLive{}.Method1(10)
  }
  
  // clobber tries to clobber unreachable memory.
  func clobber() {
  	runtime.GC()
  	for i := 1; i < 32; i++ {
  		for j := 0; j < 10; j++ {
  			obj := make([]*byte, i)
  			sink = obj
  		}
  	}
  	runtime.GC()
  }
  
  type funcLayoutTest struct {
  	rcvr, t                  Type
  	size, argsize, retOffset uintptr
  	stack                    []byte // pointer bitmap: 1 is pointer, 0 is scalar (or uninitialized)
  	gc                       []byte
  }
  
  var funcLayoutTests []funcLayoutTest
  
  func init() {
  	var argAlign uintptr = PtrSize
  	if runtime.GOARCH == "amd64p32" {
  		argAlign = 2 * PtrSize
  	}
  	roundup := func(x uintptr, a uintptr) uintptr {
  		return (x + a - 1) / a * a
  	}
  
  	funcLayoutTests = append(funcLayoutTests,
  		funcLayoutTest{
  			nil,
  			ValueOf(func(a, b string) string { return "" }).Type(),
  			6 * PtrSize,
  			4 * PtrSize,
  			4 * PtrSize,
  			[]byte{1, 0, 1},
  			[]byte{1, 0, 1, 0, 1},
  		})
  
  	var r []byte
  	if PtrSize == 4 {
  		r = []byte{0, 0, 0, 1}
  	} else {
  		r = []byte{0, 0, 1}
  	}
  	funcLayoutTests = append(funcLayoutTests,
  		funcLayoutTest{
  			nil,
  			ValueOf(func(a, b, c uint32, p *byte, d uint16) {}).Type(),
  			roundup(roundup(3*4, PtrSize)+PtrSize+2, argAlign),
  			roundup(3*4, PtrSize) + PtrSize + 2,
  			roundup(roundup(3*4, PtrSize)+PtrSize+2, argAlign),
  			r,
  			r,
  		})
  
  	funcLayoutTests = append(funcLayoutTests,
  		funcLayoutTest{
  			nil,
  			ValueOf(func(a map[int]int, b uintptr, c interface{}) {}).Type(),
  			4 * PtrSize,
  			4 * PtrSize,
  			4 * PtrSize,
  			[]byte{1, 0, 1, 1},
  			[]byte{1, 0, 1, 1},
  		})
  
  	type S struct {
  		a, b uintptr
  		c, d *byte
  	}
  	funcLayoutTests = append(funcLayoutTests,
  		funcLayoutTest{
  			nil,
  			ValueOf(func(a S) {}).Type(),
  			4 * PtrSize,
  			4 * PtrSize,
  			4 * PtrSize,
  			[]byte{0, 0, 1, 1},
  			[]byte{0, 0, 1, 1},
  		})
  
  	funcLayoutTests = append(funcLayoutTests,
  		funcLayoutTest{
  			ValueOf((*byte)(nil)).Type(),
  			ValueOf(func(a uintptr, b *int) {}).Type(),
  			roundup(3*PtrSize, argAlign),
  			3 * PtrSize,
  			roundup(3*PtrSize, argAlign),
  			[]byte{1, 0, 1},
  			[]byte{1, 0, 1},
  		})
  
  	funcLayoutTests = append(funcLayoutTests,
  		funcLayoutTest{
  			nil,
  			ValueOf(func(a uintptr) {}).Type(),
  			roundup(PtrSize, argAlign),
  			PtrSize,
  			roundup(PtrSize, argAlign),
  			[]byte{},
  			[]byte{},
  		})
  
  	funcLayoutTests = append(funcLayoutTests,
  		funcLayoutTest{
  			nil,
  			ValueOf(func() uintptr { return 0 }).Type(),
  			PtrSize,
  			0,
  			0,
  			[]byte{},
  			[]byte{},
  		})
  
  	funcLayoutTests = append(funcLayoutTests,
  		funcLayoutTest{
  			ValueOf(uintptr(0)).Type(),
  			ValueOf(func(a uintptr) {}).Type(),
  			2 * PtrSize,
  			2 * PtrSize,
  			2 * PtrSize,
  			[]byte{1},
  			[]byte{1},
  			// Note: this one is tricky, as the receiver is not a pointer. But we
  			// pass the receiver by reference to the autogenerated pointer-receiver
  			// version of the function.
  		})
  }
  
  func TestFuncLayout(t *testing.T) {
  	for _, lt := range funcLayoutTests {
  		typ, argsize, retOffset, stack, gc, ptrs := FuncLayout(lt.t, lt.rcvr)
  		if typ.Size() != lt.size {
  			t.Errorf("funcLayout(%v, %v).size=%d, want %d", lt.t, lt.rcvr, typ.Size(), lt.size)
  		}
  		if argsize != lt.argsize {
  			t.Errorf("funcLayout(%v, %v).argsize=%d, want %d", lt.t, lt.rcvr, argsize, lt.argsize)
  		}
  		if retOffset != lt.retOffset {
  			t.Errorf("funcLayout(%v, %v).retOffset=%d, want %d", lt.t, lt.rcvr, retOffset, lt.retOffset)
  		}
  		if !bytes.Equal(stack, lt.stack) {
  			t.Errorf("funcLayout(%v, %v).stack=%v, want %v", lt.t, lt.rcvr, stack, lt.stack)
  		}
  		if !bytes.Equal(gc, lt.gc) {
  			t.Errorf("funcLayout(%v, %v).gc=%v, want %v", lt.t, lt.rcvr, gc, lt.gc)
  		}
  		if ptrs && len(stack) == 0 || !ptrs && len(stack) > 0 {
  			t.Errorf("funcLayout(%v, %v) pointers flag=%v, want %v", lt.t, lt.rcvr, ptrs, !ptrs)
  		}
  	}
  }
  
  func verifyGCBits(t *testing.T, typ Type, bits []byte) {
  	heapBits := GCBits(New(typ).Interface())
  	if !bytes.Equal(heapBits, bits) {
  		t.Errorf("heapBits incorrect for %v\nhave %v\nwant %v", typ, heapBits, bits)
  	}
  }
  
  func verifyGCBitsSlice(t *testing.T, typ Type, cap int, bits []byte) {
  	// Creating a slice causes the runtime to repeat a bitmap,
  	// which exercises a different path from making the compiler
  	// repeat a bitmap for a small array or executing a repeat in
  	// a GC program.
  	val := MakeSlice(typ, 0, cap)
  	data := NewAt(ArrayOf(cap, typ), unsafe.Pointer(val.Pointer()))
  	heapBits := GCBits(data.Interface())
  	// Repeat the bitmap for the slice size, trimming scalars in
  	// the last element.
  	bits = rep(cap, bits)
  	for len(bits) > 2 && bits[len(bits)-1] == 0 {
  		bits = bits[:len(bits)-1]
  	}
  	if len(bits) == 2 && bits[0] == 0 && bits[1] == 0 {
  		bits = bits[:0]
  	}
  	if !bytes.Equal(heapBits, bits) {
  		t.Errorf("heapBits incorrect for make(%v, 0, %v)\nhave %v\nwant %v", typ, cap, heapBits, bits)
  	}
  }
  
  func TestGCBits(t *testing.T) {
  	verifyGCBits(t, TypeOf((*byte)(nil)), []byte{1})
  
  	// Building blocks for types seen by the compiler (like [2]Xscalar).
  	// The compiler will create the type structures for the derived types,
  	// including their GC metadata.
  	type Xscalar struct{ x uintptr }
  	type Xptr struct{ x *byte }
  	type Xptrscalar struct {
  		*byte
  		uintptr
  	}
  	type Xscalarptr struct {
  		uintptr
  		*byte
  	}
  	type Xbigptrscalar struct {
  		_ [100]*byte
  		_ [100]uintptr
  	}
  
  	var Tscalar, Tint64, Tptr, Tscalarptr, Tptrscalar, Tbigptrscalar Type
  	{
  		// Building blocks for types constructed by reflect.
  		// This code is in a separate block so that code below
  		// cannot accidentally refer to these.
  		// The compiler must NOT see types derived from these
  		// (for example, [2]Scalar must NOT appear in the program),
  		// or else reflect will use it instead of having to construct one.
  		// The goal is to test the construction.
  		type Scalar struct{ x uintptr }
  		type Ptr struct{ x *byte }
  		type Ptrscalar struct {
  			*byte
  			uintptr
  		}
  		type Scalarptr struct {
  			uintptr
  			*byte
  		}
  		type Bigptrscalar struct {
  			_ [100]*byte
  			_ [100]uintptr
  		}
  		type Int64 int64
  		Tscalar = TypeOf(Scalar{})
  		Tint64 = TypeOf(Int64(0))
  		Tptr = TypeOf(Ptr{})
  		Tscalarptr = TypeOf(Scalarptr{})
  		Tptrscalar = TypeOf(Ptrscalar{})
  		Tbigptrscalar = TypeOf(Bigptrscalar{})
  	}
  
  	empty := []byte{}
  
  	verifyGCBits(t, TypeOf(Xscalar{}), empty)
  	verifyGCBits(t, Tscalar, empty)
  	verifyGCBits(t, TypeOf(Xptr{}), lit(1))
  	verifyGCBits(t, Tptr, lit(1))
  	verifyGCBits(t, TypeOf(Xscalarptr{}), lit(0, 1))
  	verifyGCBits(t, Tscalarptr, lit(0, 1))
  	verifyGCBits(t, TypeOf(Xptrscalar{}), lit(1))
  	verifyGCBits(t, Tptrscalar, lit(1))
  
  	verifyGCBits(t, TypeOf([0]Xptr{}), empty)
  	verifyGCBits(t, ArrayOf(0, Tptr), empty)
  	verifyGCBits(t, TypeOf([1]Xptrscalar{}), lit(1))
  	verifyGCBits(t, ArrayOf(1, Tptrscalar), lit(1))
  	verifyGCBits(t, TypeOf([2]Xscalar{}), empty)
  	verifyGCBits(t, ArrayOf(2, Tscalar), empty)
  	verifyGCBits(t, TypeOf([10000]Xscalar{}), empty)
  	verifyGCBits(t, ArrayOf(10000, Tscalar), empty)
  	verifyGCBits(t, TypeOf([2]Xptr{}), lit(1, 1))
  	verifyGCBits(t, ArrayOf(2, Tptr), lit(1, 1))
  	verifyGCBits(t, TypeOf([10000]Xptr{}), rep(10000, lit(1)))
  	verifyGCBits(t, ArrayOf(10000, Tptr), rep(10000, lit(1)))
  	verifyGCBits(t, TypeOf([2]Xscalarptr{}), lit(0, 1, 0, 1))
  	verifyGCBits(t, ArrayOf(2, Tscalarptr), lit(0, 1, 0, 1))
  	verifyGCBits(t, TypeOf([10000]Xscalarptr{}), rep(10000, lit(0, 1)))
  	verifyGCBits(t, ArrayOf(10000, Tscalarptr), rep(10000, lit(0, 1)))
  	verifyGCBits(t, TypeOf([2]Xptrscalar{}), lit(1, 0, 1))
  	verifyGCBits(t, ArrayOf(2, Tptrscalar), lit(1, 0, 1))
  	verifyGCBits(t, TypeOf([10000]Xptrscalar{}), rep(10000, lit(1, 0)))
  	verifyGCBits(t, ArrayOf(10000, Tptrscalar), rep(10000, lit(1, 0)))
  	verifyGCBits(t, TypeOf([1][10000]Xptrscalar{}), rep(10000, lit(1, 0)))
  	verifyGCBits(t, ArrayOf(1, ArrayOf(10000, Tptrscalar)), rep(10000, lit(1, 0)))
  	verifyGCBits(t, TypeOf([2][10000]Xptrscalar{}), rep(2*10000, lit(1, 0)))
  	verifyGCBits(t, ArrayOf(2, ArrayOf(10000, Tptrscalar)), rep(2*10000, lit(1, 0)))
  	verifyGCBits(t, TypeOf([4]Xbigptrscalar{}), join(rep(3, join(rep(100, lit(1)), rep(100, lit(0)))), rep(100, lit(1))))
  	verifyGCBits(t, ArrayOf(4, Tbigptrscalar), join(rep(3, join(rep(100, lit(1)), rep(100, lit(0)))), rep(100, lit(1))))
  
  	verifyGCBitsSlice(t, TypeOf([]Xptr{}), 0, empty)
  	verifyGCBitsSlice(t, SliceOf(Tptr), 0, empty)
  	verifyGCBitsSlice(t, TypeOf([]Xptrscalar{}), 1, lit(1))
  	verifyGCBitsSlice(t, SliceOf(Tptrscalar), 1, lit(1))
  	verifyGCBitsSlice(t, TypeOf([]Xscalar{}), 2, lit(0))
  	verifyGCBitsSlice(t, SliceOf(Tscalar), 2, lit(0))
  	verifyGCBitsSlice(t, TypeOf([]Xscalar{}), 10000, lit(0))
  	verifyGCBitsSlice(t, SliceOf(Tscalar), 10000, lit(0))
  	verifyGCBitsSlice(t, TypeOf([]Xptr{}), 2, lit(1))
  	verifyGCBitsSlice(t, SliceOf(Tptr), 2, lit(1))
  	verifyGCBitsSlice(t, TypeOf([]Xptr{}), 10000, lit(1))
  	verifyGCBitsSlice(t, SliceOf(Tptr), 10000, lit(1))
  	verifyGCBitsSlice(t, TypeOf([]Xscalarptr{}), 2, lit(0, 1))
  	verifyGCBitsSlice(t, SliceOf(Tscalarptr), 2, lit(0, 1))
  	verifyGCBitsSlice(t, TypeOf([]Xscalarptr{}), 10000, lit(0, 1))
  	verifyGCBitsSlice(t, SliceOf(Tscalarptr), 10000, lit(0, 1))
  	verifyGCBitsSlice(t, TypeOf([]Xptrscalar{}), 2, lit(1, 0))
  	verifyGCBitsSlice(t, SliceOf(Tptrscalar), 2, lit(1, 0))
  	verifyGCBitsSlice(t, TypeOf([]Xptrscalar{}), 10000, lit(1, 0))
  	verifyGCBitsSlice(t, SliceOf(Tptrscalar), 10000, lit(1, 0))
  	verifyGCBitsSlice(t, TypeOf([][10000]Xptrscalar{}), 1, rep(10000, lit(1, 0)))
  	verifyGCBitsSlice(t, SliceOf(ArrayOf(10000, Tptrscalar)), 1, rep(10000, lit(1, 0)))
  	verifyGCBitsSlice(t, TypeOf([][10000]Xptrscalar{}), 2, rep(10000, lit(1, 0)))
  	verifyGCBitsSlice(t, SliceOf(ArrayOf(10000, Tptrscalar)), 2, rep(10000, lit(1, 0)))
  	verifyGCBitsSlice(t, TypeOf([]Xbigptrscalar{}), 4, join(rep(100, lit(1)), rep(100, lit(0))))
  	verifyGCBitsSlice(t, SliceOf(Tbigptrscalar), 4, join(rep(100, lit(1)), rep(100, lit(0))))
  
  	verifyGCBits(t, TypeOf((chan [100]Xscalar)(nil)), lit(1))
  	verifyGCBits(t, ChanOf(BothDir, ArrayOf(100, Tscalar)), lit(1))
  
  	verifyGCBits(t, TypeOf((func([10000]Xscalarptr))(nil)), lit(1))
  	verifyGCBits(t, FuncOf([]Type{ArrayOf(10000, Tscalarptr)}, nil, false), lit(1))
  
  	verifyGCBits(t, TypeOf((map[[10000]Xscalarptr]Xscalar)(nil)), lit(1))
  	verifyGCBits(t, MapOf(ArrayOf(10000, Tscalarptr), Tscalar), lit(1))
  
  	verifyGCBits(t, TypeOf((*[10000]Xscalar)(nil)), lit(1))
  	verifyGCBits(t, PtrTo(ArrayOf(10000, Tscalar)), lit(1))
  
  	verifyGCBits(t, TypeOf(([][10000]Xscalar)(nil)), lit(1))
  	verifyGCBits(t, SliceOf(ArrayOf(10000, Tscalar)), lit(1))
  
  	hdr := make([]byte, 8/PtrSize)
  
  	verifyMapBucket := func(t *testing.T, k, e Type, m interface{}, want []byte) {
  		verifyGCBits(t, MapBucketOf(k, e), want)
  		verifyGCBits(t, CachedBucketOf(TypeOf(m)), want)
  	}
  	verifyMapBucket(t,
  		Tscalar, Tptr,
  		map[Xscalar]Xptr(nil),
  		join(hdr, rep(8, lit(0)), rep(8, lit(1)), lit(1)))
  	verifyMapBucket(t,
  		Tscalarptr, Tptr,
  		map[Xscalarptr]Xptr(nil),
  		join(hdr, rep(8, lit(0, 1)), rep(8, lit(1)), lit(1)))
  	verifyMapBucket(t, Tint64, Tptr,
  		map[int64]Xptr(nil),
  		join(hdr, rep(8, rep(8/PtrSize, lit(0))), rep(8, lit(1)), naclpad(), lit(1)))
  	verifyMapBucket(t,
  		Tscalar, Tscalar,
  		map[Xscalar]Xscalar(nil),
  		empty)
  	verifyMapBucket(t,
  		ArrayOf(2, Tscalarptr), ArrayOf(3, Tptrscalar),
  		map[[2]Xscalarptr][3]Xptrscalar(nil),
  		join(hdr, rep(8*2, lit(0, 1)), rep(8*3, lit(1, 0)), lit(1)))
  	verifyMapBucket(t,
  		ArrayOf(64/PtrSize, Tscalarptr), ArrayOf(64/PtrSize, Tptrscalar),
  		map[[64 / PtrSize]Xscalarptr][64 / PtrSize]Xptrscalar(nil),
  		join(hdr, rep(8*64/PtrSize, lit(0, 1)), rep(8*64/PtrSize, lit(1, 0)), lit(1)))
  	verifyMapBucket(t,
  		ArrayOf(64/PtrSize+1, Tscalarptr), ArrayOf(64/PtrSize, Tptrscalar),
  		map[[64/PtrSize + 1]Xscalarptr][64 / PtrSize]Xptrscalar(nil),
  		join(hdr, rep(8, lit(1)), rep(8*64/PtrSize, lit(1, 0)), lit(1)))
  	verifyMapBucket(t,
  		ArrayOf(64/PtrSize, Tscalarptr), ArrayOf(64/PtrSize+1, Tptrscalar),
  		map[[64 / PtrSize]Xscalarptr][64/PtrSize + 1]Xptrscalar(nil),
  		join(hdr, rep(8*64/PtrSize, lit(0, 1)), rep(8, lit(1)), lit(1)))
  	verifyMapBucket(t,
  		ArrayOf(64/PtrSize+1, Tscalarptr), ArrayOf(64/PtrSize+1, Tptrscalar),
  		map[[64/PtrSize + 1]Xscalarptr][64/PtrSize + 1]Xptrscalar(nil),
  		join(hdr, rep(8, lit(1)), rep(8, lit(1)), lit(1)))
  }
  
  func naclpad() []byte {
  	if runtime.GOARCH == "amd64p32" {
  		return lit(0)
  	}
  	return nil
  }
  
  func rep(n int, b []byte) []byte { return bytes.Repeat(b, n) }
  func join(b ...[]byte) []byte    { return bytes.Join(b, nil) }
  func lit(x ...byte) []byte       { return x }
  
  func TestTypeOfTypeOf(t *testing.T) {
  	// Check that all the type constructors return concrete *rtype implementations.
  	// It's difficult to test directly because the reflect package is only at arm's length.
  	// The easiest thing to do is just call a function that crashes if it doesn't get an *rtype.
  	check := func(name string, typ Type) {
  		if underlying := TypeOf(typ).String(); underlying != "*reflect.rtype" {
  			t.Errorf("%v returned %v, not *reflect.rtype", name, underlying)
  		}
  	}
  
  	type T struct{ int }
  	check("TypeOf", TypeOf(T{}))
  
  	check("ArrayOf", ArrayOf(10, TypeOf(T{})))
  	check("ChanOf", ChanOf(BothDir, TypeOf(T{})))
  	check("FuncOf", FuncOf([]Type{TypeOf(T{})}, nil, false))
  	check("MapOf", MapOf(TypeOf(T{}), TypeOf(T{})))
  	check("PtrTo", PtrTo(TypeOf(T{})))
  	check("SliceOf", SliceOf(TypeOf(T{})))
  }
  
  type XM struct{ _ bool }
  
  func (*XM) String() string { return "" }
  
  func TestPtrToMethods(t *testing.T) {
  	var y struct{ XM }
  	yp := New(TypeOf(y)).Interface()
  	_, ok := yp.(fmt.Stringer)
  	if !ok {
  		t.Fatal("does not implement Stringer, but should")
  	}
  }
  
  func TestMapAlloc(t *testing.T) {
  	m := ValueOf(make(map[int]int, 10))
  	k := ValueOf(5)
  	v := ValueOf(7)
  	allocs := testing.AllocsPerRun(100, func() {
  		m.SetMapIndex(k, v)
  	})
  	if allocs > 0.5 {
  		t.Errorf("allocs per map assignment: want 0 got %f", allocs)
  	}
  
  	const size = 1000
  	tmp := 0
  	val := ValueOf(&tmp).Elem()
  	allocs = testing.AllocsPerRun(100, func() {
  		mv := MakeMapWithSize(TypeOf(map[int]int{}), size)
  		// Only adding half of the capacity to not trigger re-allocations due too many overloaded buckets.
  		for i := 0; i < size/2; i++ {
  			val.SetInt(int64(i))
  			mv.SetMapIndex(val, val)
  		}
  	})
  	if allocs > 10 {
  		t.Errorf("allocs per map assignment: want at most 10 got %f", allocs)
  	}
  	// Empirical testing shows that with capacity hint single run will trigger 3 allocations and without 91. I set
  	// the threshold to 10, to not make it overly brittle if something changes in the initial allocation of the
  	// map, but to still catch a regression where we keep re-allocating in the hashmap as new entries are added.
  }
  
  func TestChanAlloc(t *testing.T) {
  	// Note: for a chan int, the return Value must be allocated, so we
  	// use a chan *int instead.
  	c := ValueOf(make(chan *int, 1))
  	v := ValueOf(new(int))
  	allocs := testing.AllocsPerRun(100, func() {
  		c.Send(v)
  		_, _ = c.Recv()
  	})
  	if allocs < 0.5 || allocs > 1.5 {
  		t.Errorf("allocs per chan send/recv: want 1 got %f", allocs)
  	}
  	// Note: there is one allocation in reflect.recv which seems to be
  	// a limitation of escape analysis. If that is ever fixed the
  	// allocs < 0.5 condition will trigger and this test should be fixed.
  }
  
  type TheNameOfThisTypeIsExactly255BytesLongSoWhenTheCompilerPrependsTheReflectTestPackageNameAndExtraStarTheLinkerRuntimeAndReflectPackagesWillHaveToCorrectlyDecodeTheSecondLengthByte0123456789_0123456789_0123456789_0123456789_0123456789_012345678 int
  
  type nameTest struct {
  	v    interface{}
  	want string
  }
  
  var nameTests = []nameTest{
  	{(*int32)(nil), "int32"},
  	{(*D1)(nil), "D1"},
  	{(*[]D1)(nil), ""},
  	{(*chan D1)(nil), ""},
  	{(*func() D1)(nil), ""},
  	{(*<-chan D1)(nil), ""},
  	{(*chan<- D1)(nil), ""},
  	{(*interface{})(nil), ""},
  	{(*interface {
  		F()
  	})(nil), ""},
  	{(*TheNameOfThisTypeIsExactly255BytesLongSoWhenTheCompilerPrependsTheReflectTestPackageNameAndExtraStarTheLinkerRuntimeAndReflectPackagesWillHaveToCorrectlyDecodeTheSecondLengthByte0123456789_0123456789_0123456789_0123456789_0123456789_012345678)(nil), "TheNameOfThisTypeIsExactly255BytesLongSoWhenTheCompilerPrependsTheReflectTestPackageNameAndExtraStarTheLinkerRuntimeAndReflectPackagesWillHaveToCorrectlyDecodeTheSecondLengthByte0123456789_0123456789_0123456789_0123456789_0123456789_012345678"},
  }
  
  func TestNames(t *testing.T) {
  	for _, test := range nameTests {
  		typ := TypeOf(test.v).Elem()
  		if got := typ.Name(); got != test.want {
  			t.Errorf("%v Name()=%q, want %q", typ, got, test.want)
  		}
  	}
  }
  
  func TestExported(t *testing.T) {
  	type ΦExported struct{}
  	type φUnexported struct{}
  	type BigP *big
  	type P int
  	type p *P
  	type P2 p
  	type p3 p
  
  	type exportTest struct {
  		v    interface{}
  		want bool
  	}
  	exportTests := []exportTest{
  		{D1{}, true},
  		{(*D1)(nil), true},
  		{big{}, false},
  		{(*big)(nil), false},
  		{(BigP)(nil), true},
  		{(*BigP)(nil), true},
  		{ΦExported{}, true},
  		{φUnexported{}, false},
  		{P(0), true},
  		{(p)(nil), false},
  		{(P2)(nil), true},
  		{(p3)(nil), false},
  	}
  
  	for i, test := range exportTests {
  		typ := TypeOf(test.v)
  		if got := IsExported(typ); got != test.want {
  			t.Errorf("%d: %s exported=%v, want %v", i, typ.Name(), got, test.want)
  		}
  	}
  }
  
  type embed struct {
  	EmbedWithUnexpMeth
  }
  
  func TestNameBytesAreAligned(t *testing.T) {
  	typ := TypeOf(embed{})
  	b := FirstMethodNameBytes(typ)
  	v := uintptr(unsafe.Pointer(b))
  	if v%unsafe.Alignof((*byte)(nil)) != 0 {
  		t.Errorf("reflect.name.bytes pointer is not aligned: %x", v)
  	}
  }
  
  func TestTypeStrings(t *testing.T) {
  	type stringTest struct {
  		typ  Type
  		want string
  	}
  	stringTests := []stringTest{
  		{TypeOf(func(int) {}), "func(int)"},
  		{FuncOf([]Type{TypeOf(int(0))}, nil, false), "func(int)"},
  		{TypeOf(XM{}), "reflect_test.XM"},
  		{TypeOf(new(XM)), "*reflect_test.XM"},
  		{TypeOf(new(XM).String), "func() string"},
  		{TypeOf(new(XM)).Method(0).Type, "func(*reflect_test.XM) string"},
  		{ChanOf(3, TypeOf(XM{})), "chan reflect_test.XM"},
  		{MapOf(TypeOf(int(0)), TypeOf(XM{})), "map[int]reflect_test.XM"},
  		{ArrayOf(3, TypeOf(XM{})), "[3]reflect_test.XM"},
  		{ArrayOf(3, TypeOf(struct{}{})), "[3]struct {}"},
  	}
  
  	for i, test := range stringTests {
  		if got, want := test.typ.String(), test.want; got != want {
  			t.Errorf("type %d String()=%q, want %q", i, got, want)
  		}
  	}
  }
  
  func TestOffsetLock(t *testing.T) {
  	var wg sync.WaitGroup
  	for i := 0; i < 4; i++ {
  		i := i
  		wg.Add(1)
  		go func() {
  			for j := 0; j < 50; j++ {
  				ResolveReflectName(fmt.Sprintf("OffsetLockName:%d:%d", i, j))
  			}
  			wg.Done()
  		}()
  	}
  	wg.Wait()
  }
  
  func BenchmarkNew(b *testing.B) {
  	v := TypeOf(XM{})
  	b.RunParallel(func(pb *testing.PB) {
  		for pb.Next() {
  			New(v)
  		}
  	})
  }
  
  func TestSwapper(t *testing.T) {
  	type I int
  	var a, b, c I
  	type pair struct {
  		x, y int
  	}
  	type pairPtr struct {
  		x, y int
  		p    *I
  	}
  	type S string
  
  	tests := []struct {
  		in   interface{}
  		i, j int
  		want interface{}
  	}{
  		{
  			in:   []int{1, 20, 300},
  			i:    0,
  			j:    2,
  			want: []int{300, 20, 1},
  		},
  		{
  			in:   []uintptr{1, 20, 300},
  			i:    0,
  			j:    2,
  			want: []uintptr{300, 20, 1},
  		},
  		{
  			in:   []int16{1, 20, 300},
  			i:    0,
  			j:    2,
  			want: []int16{300, 20, 1},
  		},
  		{
  			in:   []int8{1, 20, 100},
  			i:    0,
  			j:    2,
  			want: []int8{100, 20, 1},
  		},
  		{
  			in:   []*I{&a, &b, &c},
  			i:    0,
  			j:    2,
  			want: []*I{&c, &b, &a},
  		},
  		{
  			in:   []string{"eric", "sergey", "larry"},
  			i:    0,
  			j:    2,
  			want: []string{"larry", "sergey", "eric"},
  		},
  		{
  			in:   []S{"eric", "sergey", "larry"},
  			i:    0,
  			j:    2,
  			want: []S{"larry", "sergey", "eric"},
  		},
  		{
  			in:   []pair{{1, 2}, {3, 4}, {5, 6}},
  			i:    0,
  			j:    2,
  			want: []pair{{5, 6}, {3, 4}, {1, 2}},
  		},
  		{
  			in:   []pairPtr{{1, 2, &a}, {3, 4, &b}, {5, 6, &c}},
  			i:    0,
  			j:    2,
  			want: []pairPtr{{5, 6, &c}, {3, 4, &b}, {1, 2, &a}},
  		},
  	}
  
  	for i, tt := range tests {
  		inStr := fmt.Sprint(tt.in)
  		Swapper(tt.in)(tt.i, tt.j)
  		if !DeepEqual(tt.in, tt.want) {
  			t.Errorf("%d. swapping %v and %v of %v = %v; want %v", i, tt.i, tt.j, inStr, tt.in, tt.want)
  		}
  	}
  }
  
  // TestUnaddressableField tests that the reflect package will not allow
  // a type from another package to be used as a named type with an
  // unexported field.
  //
  // This ensures that unexported fields cannot be modified by other packages.
  func TestUnaddressableField(t *testing.T) {
  	var b Buffer // type defined in reflect, a different package
  	var localBuffer struct {
  		buf []byte
  	}
  	lv := ValueOf(&localBuffer).Elem()
  	rv := ValueOf(b)
  	shouldPanic(func() {
  		lv.Set(rv)
  	})
  }
  
  type Tint int
  
  type Tint2 = Tint
  
  type Talias1 struct {
  	byte
  	uint8
  	int
  	int32
  	rune
  }
  
  type Talias2 struct {
  	Tint
  	Tint2
  }
  
  func TestAliasNames(t *testing.T) {
  	t1 := Talias1{byte: 1, uint8: 2, int: 3, int32: 4, rune: 5}
  	out := fmt.Sprintf("%#v", t1)
  	want := "reflect_test.Talias1{byte:0x1, uint8:0x2, int:3, int32:4, rune:5}"
  	if out != want {
  		t.Errorf("Talias1 print:\nhave: %s\nwant: %s", out, want)
  	}
  
  	t2 := Talias2{Tint: 1, Tint2: 2}
  	out = fmt.Sprintf("%#v", t2)
  	want = "reflect_test.Talias2{Tint:1, Tint2:2}"
  	if out != want {
  		t.Errorf("Talias2 print:\nhave: %s\nwant: %s", out, want)
  	}
  }
  

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