| // run | |
| // Copyright 2020 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. | |
| // Issue #43480: ICE on large uint64 constants in switch cases. | |
| package main | |
| func isPow10(x uint64) bool { | |
| switch x { | |
| case 1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9, | |
| 1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19: | |
| return true | |
| } | |
| return false | |
| } | |
| func main() { | |
| var x uint64 = 1 | |
| for { | |
| if !isPow10(x) || isPow10(x-1) || isPow10(x+1) { | |
| panic(x) | |
| } | |
| next := x * 10 | |
| if next/10 != x { | |
| break // overflow | |
| } | |
| x = next | |
| } | |
| } |