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// 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
}
}
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