mirror of
https://github.com/golang/go
synced 2024-11-15 00:10:28 -07:00
65 lines
1.2 KiB
Go
65 lines
1.2 KiB
Go
|
// run
|
||
|
|
|
||
|
|
// Copyright 2018 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.
|
||
|
|
|
||
|
|
// Check all ways to compare a non-constant string to the empty string.
|
||
|
|
|
||
|
|
package main
|
||
|
|
|
||
|
|
import (
|
||
|
|
"fmt"
|
||
|
|
"os"
|
||
|
|
)
|
||
|
|
|
||
|
|
var (
|
||
|
|
s = "abc"
|
||
|
|
e = ""
|
||
|
|
failed bool
|
||
|
|
)
|
||
|
|
|
||
|
|
func main() {
|
||
|
|
want(true, "" < s, `"" < s`)
|
||
|
|
want(false, s < "", `s < ""`)
|
||
|
|
want(false, "" < e, `"" < e`)
|
||
|
|
want(false, e < "", `e < ""`)
|
||
|
|
|
||
|
|
want(true, "" <= s, `"" <= s`)
|
||
|
|
want(false, s <= "", `s <= ""`)
|
||
|
|
want(true, "" <= e, `"" <= e`)
|
||
|
|
want(true, e <= "", `e <= ""`)
|
||
|
|
|
||
|
|
want(false, "" > s, `"" > s`)
|
||
|
|
want(true, s > "", `s > ""`)
|
||
|
|
want(false, "" > e, `"" > e`)
|
||
|
|
want(false, e > "", `e > ""`)
|
||
|
|
|
||
|
|
want(false, "" >= s, `"" >= s`)
|
||
|
|
want(true, s >= "", `s >= ""`)
|
||
|
|
want(true, "" >= e, `"" >= e`)
|
||
|
|
want(true, e >= "", `e >= ""`)
|
||
|
|
|
||
|
|
want(false, "" == s, `"" == s`)
|
||
|
|
want(false, s == "", `s == ""`)
|
||
|
|
want(true, "" == e, `"" == e`)
|
||
|
|
want(true, e == "", `e == ""`)
|
||
|
|
|
||
|
|
want(true, "" != s, `"" != s`)
|
||
|
|
want(true, s != "", `s != ""`)
|
||
|
|
want(false, "" != e, `"" != e`)
|
||
|
|
want(false, e != "", `e != ""`)
|
||
|
|
|
||
|
|
if failed {
|
||
|
|
os.Exit(1)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
//go:noinline
|
||
|
|
func want(b bool, have bool, msg string) {
|
||
|
|
if b != have {
|
||
|
|
fmt.Println(msg)
|
||
|
|
failed = true
|
||
|
|
}
|
||
|
|
}
|