mirror of
https://github.com/golang/go
synced 2024-11-22 21:30:02 -07:00
e24977d231
The next CL will remove the -G flag, effectively hard-coding it to its current default (-G=3). Change-Id: Ib4743b529206928f9f1cca9fdb19989728327831 Reviewed-on: https://go-review.googlesource.com/c/go/+/388534 Reviewed-by: Keith Randall <khr@golang.org> Trust: Matthew Dempsky <mdempsky@google.com> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
87 lines
1.4 KiB
Go
87 lines
1.4 KiB
Go
// run
|
|
|
|
// 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
|
|
|
|
func f[T any](x interface{}) T {
|
|
return x.(T)
|
|
}
|
|
func f2[T any](x interface{}) (T, bool) {
|
|
t, ok := x.(T)
|
|
return t, ok
|
|
}
|
|
|
|
type I interface {
|
|
foo()
|
|
}
|
|
|
|
type myint int
|
|
|
|
func (myint) foo() {
|
|
}
|
|
|
|
type myfloat float64
|
|
|
|
func (myfloat) foo() {
|
|
}
|
|
|
|
func g[T I](x I) T {
|
|
return x.(T)
|
|
}
|
|
func g2[T I](x I) (T, bool) {
|
|
t, ok := x.(T)
|
|
return t, ok
|
|
}
|
|
|
|
func h[T any](x interface{}) struct{ a, b T } {
|
|
return x.(struct{ a, b T })
|
|
}
|
|
|
|
func k[T any](x interface{}) interface{ bar() T } {
|
|
return x.(interface{ bar() T })
|
|
}
|
|
|
|
type mybar int
|
|
|
|
func (x mybar) bar() int {
|
|
return int(x)
|
|
}
|
|
|
|
func main() {
|
|
var i interface{} = int(3)
|
|
var j I = myint(3)
|
|
var x interface{} = float64(3)
|
|
var y I = myfloat(3)
|
|
|
|
println(f[int](i))
|
|
shouldpanic(func() { f[int](x) })
|
|
println(f2[int](i))
|
|
println(f2[int](x))
|
|
|
|
println(g[myint](j))
|
|
shouldpanic(func() { g[myint](y) })
|
|
println(g2[myint](j))
|
|
println(g2[myint](y))
|
|
|
|
println(h[int](struct{ a, b int }{3, 5}).a)
|
|
|
|
println(k[int](mybar(3)).bar())
|
|
|
|
type large struct {a,b,c,d,e,f int}
|
|
println(f[large](large{}).a)
|
|
l2, ok := f2[large](large{})
|
|
println(l2.a, ok)
|
|
}
|
|
func shouldpanic(x func()) {
|
|
defer func() {
|
|
e := recover()
|
|
if e == nil {
|
|
panic("didn't panic")
|
|
}
|
|
}()
|
|
x()
|
|
}
|