codekingpro/portable-devtools

1// run2 3// Copyright 2022 The Go Authors. All rights reserved.4// Use of this source code is governed by a BSD-style5// license that can be found in the LICENSE file.6 7package main8 9func returnOption[T any](n int) Option[T] {10	if n == 1 {11		return Some[T]{}12	} else {13		return None{}14	}15}16 17type Option[T any] interface {18	sealedOption()19}20 21type Some[T any] struct {22	val T23}24 25func (s Some[T]) Value() T {26	return s.val27}28 29func (s Some[T]) sealedOption() {}30 31type None struct{}32 33func (s None) sealedOption() {}34 35func main() {36	s := returnOption[int](1)37	_ = s.(Some[int])38 39	s = returnOption[int](0)40	_ = s.(None)41 42	switch (any)(s).(type) {43	case Some[int]:44		panic("s is a Some[int]")45	case None:46		// ok47	default:48		panic("oops")49	}50}51