Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Empty struct comparison behavior is inconsistent #43755

Closed
kangxiaoning opened this issue Jan 18, 2021 · 1 comment
Closed

Empty struct comparison behavior is inconsistent #43755

kangxiaoning opened this issue Jan 18, 2021 · 1 comment
Labels
FrozenDueToAge

Comments

@kangxiaoning
Copy link

Empty struct comparison behavior is inconsistent, when fmt.Printf("%p, %p\n", &a, &b) exist &a == &b is true, otherwise the result is false. I think the printf statement shoult not affect the comparison result.

package main

import (
	"fmt"
)

func main() {
	var a, b struct{}
	fmt.Printf("%p, %p\n", &a, &b)
	fmt.Println(&a == &b)
	// Output:
	// 0x585448, 0x585448
	// true

	var x, y struct{}
	fmt.Println(&x == &y)
	// Output:
	// false
}

What version of Go are you using (go version)?

$ go version
go version go1.15.5 darwin/amd64

Does this issue reproduce with the latest release?

Yes，on play.golang.org got the same result.
https://play.golang.org/p/A-KTgM3J4wQ

What operating system and processor architecture are you using (go env)?

go env Output
$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/kangxiaoning/Library/Caches/go-build"
GOENV="/Users/kangxiaoning/Library/Application Support/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/Users/kangxiaoning/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/kangxiaoning/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/Cellar/go/1.15.5/libexec"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.15.5/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/xn/2nw86cd16dz_plwqff0ctk400000gn/T/go-build572142477=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

Regardless of whether fmt.Printf("%p, %p\n", &a, &b) exists or not, the result should be consistent

https://play.golang.org/p/A-KTgM3J4wQ

What did you expect to see?

true
true

What did you see instead?

true
false
@randall77
Copy link
Contributor

Dup of #12726 (and earlier). Please reopen if you disagree.

@mdempsky mdempsky mentioned this issue Jan 22, 2021
Closed
@golang golang locked and limited conversation to collaborators Jan 18, 2022
Sign up for free to subscribe to this conversation on GitHub. Already have an account? Sign in.
Assignees
No one assigned
Labels
FrozenDueToAge
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
3 participants
@randall77 @gopherbot @kangxiaoning