pragma solidity ^0.4.18; // ---------------------------------------------------------------------------- // Safe maths // ---------------------------------------------------------------------------- contract SafeMath { function safeAdd(uint a, uint b) public pure returns (uint c) { c = a + b; require(c >= a); } function safeSub(uint a, uint b) public pure returns (uint c) { require(b <= a); c = a - b; } function safeMul(uint a, uint b) public pure returns (uint c) { c = a * b; require(a == 0 || c / a == b); } function safeDiv(uint a, uint b) public pure returns (uint c) { require(b > 0); c = a / b; } }
0.4.18