// 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 import ( "fmt" "reflect" ) type G[T any] interface { g() func()(*T) } type Foo[T any] struct { } // OCALL func (l *Foo[T]) f1() (*T) { return g[T]()() } // OCALLFUNC func (l *Foo[T]) f2() (*T) { var f = g[T] return f()() } // OCALLMETH func (l *Foo[T]) f3() (*T) { return l.g()() } // OCALLINTER func (l *Foo[T]) f4() (*T) { var g G[T] = l return g.g()() } // ODYNAMICDOTTYPE func (l *Foo[T]) f5() (*T) { var x interface{} x = g[T] return x.(func()func()(*T))()() } func (l *Foo[T]) g() func() (*T) { return func() (*T) { t := new(T) reflect.ValueOf(t).Elem().SetInt(100) return t } } func g[T any]() func() (*T) { return func() (*T) { t := new(T) reflect.ValueOf(t).Elem().SetInt(100) return t } } func main() { foo := Foo[int]{} // Make sure the function conversion is correct if n := *(foo.f1()) ; n != 100{ panic(fmt.Sprintf("%v",n)) } if n := *(foo.f2()) ; n != 100{ panic(fmt.Sprintf("%v",n)) } if n := *(foo.f3()) ; n != 100{ panic(fmt.Sprintf("%v",n)) } if n := *(foo.f4()) ; n != 100{ panic(fmt.Sprintf("%v",n)) } if n := *(foo.f5()) ; n != 100{ panic(fmt.Sprintf("%v",n)) } }