go/test/typeparam/issue47708.go
korzhao 5670ff4ae5 cmd/compile: fix conversions from TypeParam to interface
If the TypeParam has all the methods of an interface, allow conversions from TypeParam to interface

Fixes #47708

Change-Id: I40a82a31f6ea9354130dbe3bcfc83537094bf12c
Reviewed-on: https://go-review.googlesource.com/c/go/+/342509
Reviewed-by: Dan Scales <danscales@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
Trust: Dan Scales <danscales@google.com>
Trust: Keith Randall <khr@golang.org>
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
2021-09-01 16:45:26 +00:00

40 lines
722 B
Go

// run -gcflags=-G=3
// Copyright 2021 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 main
import (
"fmt"
)
type FooType[T any] interface {
Foo(BarType[T])string
}
type BarType[T any] interface {
Bar(FooType[T])string
}
type Baz[T any] T
func (l Baz[T]) Foo(v BarType[T]) string {
return v.Bar(l)
}
type Bob[T any] T
func (l Bob[T]) Bar(v FooType[T]) string {
if v,ok := v.(Baz[T]);ok{
return fmt.Sprintf("%v%v",v,l)
}
return ""
}
func main() {
var baz Baz[int] = 123
var bob Bob[int] = 456
if got, want := baz.Foo(bob), "123456"; got != want {
panic(fmt.Sprintf("got %s want %s", got, want))
}
}