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

$ go version
go version devel go1.17-22f5ece3b13 Thu May 27 23:54:29 2021 +0000 windows/amd64

What did you do?

type IBase interface {
	GetName() string
}

type Item struct {
	Name  string
}

func (p Item) GetName() string {
	return p.Name
}

var funcMap = map[reflect.Type]func(interface{})IBase{}

func AddCallback[T IBase](in T) {
	funcMap[reflect.TypeOf(in)] = func(src interface{}) IBase {
		return src.(T)
	}
}

func main() {
	item := Item{
		Name : "hello",
	}

	AddCallback[Item](item)
}

What did you expect to see?

What did you see instead?

# go_generic_test
.\main.go:119:3: cannot use T₈ value as type IBase in assignment:
	T₈ does not implement IBase (missing GetName method)