mirror of
https://github.com/golang/go
synced 2024-11-25 05:47:57 -07:00
86 lines
1.6 KiB
Go
86 lines
1.6 KiB
Go
// run
|
|
|
|
// Copyright 2009 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.
|
|
|
|
// Test simple type switches on basic types.
|
|
|
|
package main
|
|
|
|
import "fmt"
|
|
|
|
const (
|
|
a = iota
|
|
b
|
|
c
|
|
d
|
|
e
|
|
)
|
|
|
|
var x = []int{1, 2, 3}
|
|
|
|
func f(x int, len *byte) {
|
|
*len = byte(x)
|
|
}
|
|
|
|
func whatis(x interface{}) string {
|
|
switch xx := x.(type) {
|
|
default:
|
|
return fmt.Sprint("default ", xx)
|
|
case int, int8, int16, int32:
|
|
return fmt.Sprint("signed ", xx)
|
|
case int64:
|
|
return fmt.Sprint("signed64 ", int64(xx))
|
|
case uint, uint8, uint16, uint32:
|
|
return fmt.Sprint("unsigned ", xx)
|
|
case uint64:
|
|
return fmt.Sprint("unsigned64 ", uint64(xx))
|
|
case nil:
|
|
return fmt.Sprint("nil ", xx)
|
|
}
|
|
panic("not reached")
|
|
}
|
|
|
|
func whatis1(x interface{}) string {
|
|
xx := x
|
|
switch xx.(type) {
|
|
default:
|
|
return fmt.Sprint("default ", xx)
|
|
case int, int8, int16, int32:
|
|
return fmt.Sprint("signed ", xx)
|
|
case int64:
|
|
return fmt.Sprint("signed64 ", xx.(int64))
|
|
case uint, uint8, uint16, uint32:
|
|
return fmt.Sprint("unsigned ", xx)
|
|
case uint64:
|
|
return fmt.Sprint("unsigned64 ", xx.(uint64))
|
|
case nil:
|
|
return fmt.Sprint("nil ", xx)
|
|
}
|
|
panic("not reached")
|
|
}
|
|
|
|
func check(x interface{}, s string) {
|
|
w := whatis(x)
|
|
if w != s {
|
|
fmt.Println("whatis", x, "=>", w, "!=", s)
|
|
panic("fail")
|
|
}
|
|
|
|
w = whatis1(x)
|
|
if w != s {
|
|
fmt.Println("whatis1", x, "=>", w, "!=", s)
|
|
panic("fail")
|
|
}
|
|
}
|
|
|
|
func main() {
|
|
check(1, "signed 1")
|
|
check(uint(1), "unsigned 1")
|
|
check(int64(1), "signed64 1")
|
|
check(uint64(1), "unsigned64 1")
|
|
check(1.5, "default 1.5")
|
|
check(nil, "nil <nil>")
|
|
}
|