/*
 * Copyright (C) 2018 The ontology Authors
 * This file is part of The ontology library.
 *
 * The ontology 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 ontology 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 ontology.  If not, see <http://www.gnu.org/licenses/>.
 */

package polynetwork

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
}
