// 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 Temp[T any] struct { } var temp, temp1 any var ch any func (it Temp[T]) HasNext() bool { var ok bool temp1 = <-ch.(chan T) // test conversion of T to interface{} during an OAS2RECV temp, ok = <-ch.(chan T) return ok } type MyInt int func (i MyInt) String() string { return "a" } type Stringer interface { String() string } type Temp2[T Stringer] struct { } var temp2 Stringer func (it Temp2[T]) HasNext() string { var x map[int]T var ok bool // test conversion of T to Stringer during an OAS2MAPR temp2, ok = x[43] _ = ok return temp2.String() } func main() { ch1 := make(chan int, 2) ch1 <- 5 ch1 <- 6 ch = ch1 iter := Temp[int]{} iter.HasNext() iter2 := Temp2[MyInt]{} if got, want := iter2.HasNext(), "a"; got != want { panic(fmt.Sprintf("got %v, want %v", got, want)) } }