// 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) | |
} | |
} |