| // run | |
| // Copyright 2020 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 | |
| var ch chan int | |
| var x int | |
| func f() int { | |
| close(ch) | |
| ch = nil | |
| return 0 | |
| } | |
| func g() int { | |
| ch = nil | |
| x = 0 | |
| return 0 | |
| } | |
| func main() { | |
| var nilch chan int | |
| var v int | |
| var ok bool | |
| _, _ = v, ok | |
| ch = make(chan int) | |
| select { | |
| case <-ch: | |
| case nilch <- f(): | |
| } | |
| ch = make(chan int) | |
| select { | |
| case v = <-ch: | |
| case nilch <- f(): | |
| } | |
| ch = make(chan int) | |
| select { | |
| case v := <-ch: _ = v | |
| case nilch <- f(): | |
| } | |
| ch = make(chan int) | |
| select { | |
| case v, ok = <-ch: | |
| case nilch <- f(): | |
| } | |
| ch = make(chan int) | |
| select { | |
| case v, ok := <-ch: _, _ = v, ok | |
| case nilch <- f(): | |
| } | |
| ch1 := make(chan int, 1) | |
| ch = ch1 | |
| x = 42 | |
| select { | |
| case ch <- x: | |
| case nilch <- g(): | |
| } | |
| if got := <-ch1; got != 42 { | |
| panic(got) | |
| } | |
| } |