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// run
// Copyright 2016 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 (
"log"
"reflect"
)
func test(got, want interface{}) {
if !reflect.DeepEqual(got, want) {
log.Fatalf("got %v, want %v", got, want)
}
}
func main() {
var i int
var ip *int
var ok interface{}
// Channel receives.
c := make(chan int, 1)
c2 := make(chan int)
c <- 42
i, ok = <-c
test(i, 42)
test(ok, true)
c <- 42
_, ok = <-c
test(ok, true)
c <- 42
select {
case i, ok = <-c:
test(i, 42)
test(ok, true)
}
c <- 42
select {
case _, ok = <-c:
test(ok, true)
}
c <- 42
select {
case i, ok = <-c:
test(i, 42)
test(ok, true)
default:
log.Fatal("bad select")
}
c <- 42
select {
case _, ok = <-c:
test(ok, true)
default:
log.Fatal("bad select")
}
c <- 42
select {
case i, ok = <-c:
test(i, 42)
test(ok, true)
case <-c2:
log.Fatal("bad select")
}
c <- 42
select {
case _, ok = <-c:
test(ok, true)
case <-c2:
log.Fatal("bad select")
}
close(c)
i, ok = <-c
test(i, 0)
test(ok, false)
_, ok = <-c
test(ok, false)
// Map indexing.
m := make(map[int]int)
i, ok = m[0]
test(i, 0)
test(ok, false)
_, ok = m[0]
test(ok, false)
m[0] = 42
i, ok = m[0]
test(i, 42)
test(ok, true)
_, ok = m[0]
test(ok, true)
// Type assertions.
var u interface{}
i, ok = u.(int)
test(i, 0)
test(ok, false)
ip, ok = u.(*int)
test(ip, (*int)(nil))
test(ok, false)
_, ok = u.(int)
test(ok, false)
u = 42
i, ok = u.(int)
test(i, 42)
test(ok, true)
_, ok = u.(int)
test(ok, true)
u = &i
ip, ok = u.(*int)
test(ip, &i)
test(ok, true)
_, ok = u.(*int)
test(ok, true)
}
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