| Linux in-mum-web1499.main-hosting.eu 5.14.0-503.40.1.el9_5.x86_64 #1 SMP PREEMPT_DYNAMIC Mon May 5 06:06:04 EDT 2025 x86_64 Path : /opt/golang/1.22.0/test/typeparam/ |
| Current File : //opt/golang/1.22.0/test/typeparam/issue47272.go |
// 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 (
"errors"
"fmt"
)
type Option[T any] struct {
ok bool
val T
}
func (o Option[T]) String() string {
if o.ok {
return fmt.Sprintf("Some(%v)", o.val)
}
return "None"
}
func Some[T any](val T) Option[T] { return Option[T]{ok: true, val: val} }
func None[T any]() Option[T] { return Option[T]{ok: false} }
type Result[T, E any] struct {
ok bool
val T
err E
}
func (r Result[T, E]) String() string {
if r.ok {
return fmt.Sprintf("Ok(%v)", r.val)
}
return fmt.Sprintf("Err(%v)", r.err)
}
func Ok[T, E any](val T) Result[T, E] { return Result[T, E]{ok: true, val: val} }
func Err[T, E any](err E) Result[T, E] { return Result[T, E]{ok: false, err: err} }
func main() {
a := Some[int](1)
b := None[int]()
fmt.Println(a, b)
x := Ok[int, error](1)
y := Err[int, error](errors.New("test"))
fmt.Println(x, y)
// fmt.Println(x)
_, _, _, _ = a, b, x, y
}