// compile // Copyright 2022 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 type Set[T comparable] map[T]struct{} func (s Set[T]) Add() Set[T] { return s } func (s Set[T]) Copy() Set[T] { return Set[T].Add(s) } func main() { _ = Set[int]{42: {}} }