1175598e42
start to standardize syntax 4 spaces/tab add implementation reference links improve tests
30 lines
951 B
Solidity
30 lines
951 B
Solidity
// based on https://github.com/OpenZeppelin/openzeppelin-contracts/blob/2f9ae975c8bdc5c7f7fa26204896f6c717f07164/contracts/math/SafeMath.sol
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pragma solidity 0.5.12;
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library SafeMath {
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function add(uint256 a, uint256 b) internal pure returns (uint256) {
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uint256 c = a + b;
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require(c >= a, "SafeMath: addition overflow");
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return c;
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}
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function sub(uint256 a, uint256 b) internal pure returns (uint256) {
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require(b <= a, "SafeMath: subtraction overflow");
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uint256 c = a - b;
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return c;
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}
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function mul(uint256 a, uint256 b) internal pure returns (uint256) {
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if (a == 0) return 0;
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uint256 c = a * b;
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require(c / a == b, "SafeMath: multiplication overflow");
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return c;
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}
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function div(uint256 a, uint256 b) internal pure returns (uint256) {
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require(b > 0, "SafeMath: division by zero");
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uint256 c = a / b;
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return c;
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}
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}
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