mirror of
https://github.com/golang/go
synced 2024-11-25 08:07:57 -07:00
85 lines
1.6 KiB
Go
85 lines
1.6 KiB
Go
// $G $D/$F.go && $L $F.$A && ./$A.out
|
|
|
|
// 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.
|
|
|
|
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();
|
|
}
|
|
|
|
w = whatis1(x);
|
|
if w != s {
|
|
fmt.Println("whatis1", x, "=>", w, "!=", s);
|
|
panic();
|
|
}
|
|
}
|
|
|
|
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>");
|
|
}
|
|
|