mirror of
https://github.com/golang/go
synced 2024-11-17 19:54:45 -07:00
54 lines
867 B
Go
54 lines
867 B
Go
|
// run
|
||
|
|
|
||
|
|
// Copyright 2017 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.
|
||
|
|
|
||
|
|
// This test makes sure that itabs are unique.
|
||
|
|
// More explicitly, we require that only one itab structure exists for the pair of
|
||
|
|
// a given compile-time interface type and underlying concrete type.
|
||
|
|
// Ensuring this invariant enables fixes for 18492 (improve type switch code).
|
||
|
|
|
||
|
|
package main
|
||
|
|
|
||
|
|
type I interface {
|
||
|
|
M()
|
||
|
|
}
|
||
|
|
type J interface {
|
||
|
|
M()
|
||
|
|
}
|
||
|
|
|
||
|
|
type T struct{}
|
||
|
|
|
||
|
|
func (*T) M() {}
|
||
|
|
|
||
|
|
func main() {
|
||
|
|
test1()
|
||
|
|
test2()
|
||
|
|
}
|
||
|
|
|
||
|
|
func test1() {
|
||
|
|
t := new(T)
|
||
|
|
var i1, i2 I
|
||
|
|
var j interface {
|
||
|
|
M()
|
||
|
|
}
|
||
|
|
i1 = t
|
||
|
|
j = t
|
||
|
|
i2 = j
|
||
|
|
if i1 != i2 {
|
||
|
|
panic("interfaces not equal")
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
func test2() {
|
||
|
|
t := new(T)
|
||
|
|
i1 := (I)(t)
|
||
|
|
i2 := (I)((interface {
|
||
|
|
M()
|
||
|
|
})((J)(t)))
|
||
|
|
if i1 != i2 {
|
||
|
|
panic("interfaces not equal")
|
||
|
|
}
|
||
|
|
}
|