|  | // 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. | 
|  |  | 
|  | package main | 
|  |  | 
|  | import "fmt" | 
|  |  | 
|  | func f0() string { | 
|  | const f = 3.141592; | 
|  | return fmt.Sprintf("%v", float64(f)); | 
|  | } | 
|  |  | 
|  |  | 
|  | func f1() string { | 
|  | const f = 3.141592; | 
|  | x := float64(float32(f));  // appears to change the precision of f | 
|  | _ = x; | 
|  | return fmt.Sprintf("%v", float64(f)); | 
|  | } | 
|  |  | 
|  |  | 
|  | func main() { | 
|  | r0 := f0(); | 
|  | r1 := f1(); | 
|  | if r0 != r1 { | 
|  | println("r0 =", r0); | 
|  | println("r1 =", r1); | 
|  | panic("r0 and r1 should be the same"); | 
|  | } | 
|  | } |