laconicd-deprecated/tests/solidity/suites/staking/contracts/lib/os/SafeMath64.sol

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// Brought from https://github.com/aragon/aragonOS/blob/v4.3.0/contracts/lib/math/SafeMath64.sol
// Adapted to use pragma ^0.5.8 and satisfy our linter rules
pragma solidity ^0.5.8;
/**
* @title SafeMath64
* @dev Math operations for uint64 with safety checks that revert on error
*/
library SafeMath64 {
string private constant ERROR_ADD_OVERFLOW = "MATH64_ADD_OVERFLOW";
string private constant ERROR_SUB_UNDERFLOW = "MATH64_SUB_UNDERFLOW";
string private constant ERROR_MUL_OVERFLOW = "MATH64_MUL_OVERFLOW";
string private constant ERROR_DIV_ZERO = "MATH64_DIV_ZERO";
/**
* @dev Multiplies two numbers, reverts on overflow.
*/
function mul(uint64 _a, uint64 _b) internal pure returns (uint64) {
uint256 c = uint256(_a) * uint256(_b);
require(c < 0x010000000000000000, ERROR_MUL_OVERFLOW); // 2**64 (less gas this way)
return uint64(c);
}
/**
* @dev Integer division of two numbers truncating the quotient, reverts on division by zero.
*/
function div(uint64 _a, uint64 _b) internal pure returns (uint64) {
require(_b > 0, ERROR_DIV_ZERO); // Solidity only automatically asserts when dividing by 0
uint64 c = _a / _b;
// assert(_a == _b * c + _a % _b); // There is no case in which this doesn't hold
return c;
}
/**
* @dev Subtracts two numbers, reverts on overflow (i.e. if subtrahend is greater than minuend).
*/
function sub(uint64 _a, uint64 _b) internal pure returns (uint64) {
require(_b <= _a, ERROR_SUB_UNDERFLOW);
uint64 c = _a - _b;
return c;
}
/**
* @dev Adds two numbers, reverts on overflow.
*/
function add(uint64 _a, uint64 _b) internal pure returns (uint64) {
uint64 c = _a + _b;
require(c >= _a, ERROR_ADD_OVERFLOW);
return c;
}
/**
* @dev Divides two numbers and returns the remainder (unsigned integer modulo),
* reverts when dividing by zero.
*/
function mod(uint64 a, uint64 b) internal pure returns (uint64) {
require(b != 0, ERROR_DIV_ZERO);
return a % b;
}
}