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// 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.
// Test that we can convert type parameters to both empty
// and nonempty interfaces, and named and nonnamed versions
// thereof.
package main
import "fmt"
type E interface{}
func f[T any](x T) interface{} {
var i interface{} = x
return i
}
func fs[T any](x T) interface{} {
y := []T{x}
var i interface{} = y
return i
}
func g[T any](x T) E {
var i E = x
return i
}
type C interface {
foo() int
}
type myInt int
func (x myInt) foo() int {
return int(x + 1)
}
func h[T C](x T) interface{ foo() int } {
var i interface{ foo() int } = x
return i
}
func i[T C](x T) C {
var i C = x // conversion in assignment
return i
}
func j[T C](t T) C {
return C(t) // explicit conversion
}
func js[T any](x T) interface{} {
y := []T{x}
return interface{}(y)
}
func main() {
if got, want := f[int](7), 7; got != want {
panic(fmt.Sprintf("got %d want %d", got, want))
}
if got, want := fs[int](7), []int{7}; got.([]int)[0] != want[0] {
panic(fmt.Sprintf("got %d want %d", got, want))
}
if got, want := g[int](7), 7; got != want {
panic(fmt.Sprintf("got %d want %d", got, want))
}
if got, want := h[myInt](7).foo(), 8; got != want {
panic(fmt.Sprintf("got %d want %d", got, want))
}
if got, want := i[myInt](7).foo(), 8; got != want {
panic(fmt.Sprintf("got %d want %d", got, want))
}
if got, want := j[myInt](7).foo(), 8; got != want {
panic(fmt.Sprintf("got %d want %d", got, want))
}
if got, want := js[int](7), []int{7}; got.([]int)[0] != want[0] {
panic(fmt.Sprintf("got %d want %d", got, want))
}
}
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