/
safeMath.go
41 lines (35 loc) · 1.13 KB
/
safeMath.go
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/*
* Copyright (C) 2021 The poly network Authors
* This file is part of The poly network library.
*
* The poly network is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* The poly network is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with the poly network. If not, see <http://www.gnu.org/licenses/>.
*/
package common
import "math"
const (
MAX_UINT64 = math.MaxUint64
MAX_INT64 = math.MaxInt64
)
func SafeSub(x, y uint64) (uint64, bool) {
return x - y, x < y
}
func SafeAdd(x, y uint64) (uint64, bool) {
return x + y, y > MAX_UINT64-x
}
func SafeMul(x, y uint64) (uint64, bool) {
if x == 0 || y == 0 {
return 0, false
}
return x * y, y > MAX_UINT64/x
}