47 lines
1.2 KiB
Solidity
47 lines
1.2 KiB
Solidity
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pragma solidity ^0.4.21;
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/**
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* Math operations with safety checks
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*/
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library SafeMath {
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function mul(uint a, uint b) internal pure returns (uint) {
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uint c = a * b;
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assert(a == 0 || c / a == b);
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return c;
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}
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function div(uint a, uint b) internal pure returns (uint) {
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// assert(b > 0); // Solidity automatically throws when dividing by 0
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uint c = a / b;
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// assert(a == b * c + a % b); // There is no case in which this doesn't hold
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return c;
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}
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function sub(uint a, uint b) internal pure returns (uint) {
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assert(b <= a);
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return a - b;
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}
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function add(uint a, uint b) internal pure returns (uint) {
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uint c = a + b;
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assert(c >= a);
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return c;
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}
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function max64(uint64 a, uint64 b) internal pure returns (uint64) {
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return a >= b ? a : b;
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}
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function min64(uint64 a, uint64 b) internal pure returns (uint64) {
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return a < b ? a : b;
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}
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function max256(uint256 a, uint256 b) internal pure returns (uint256) {
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return a >= b ? a : b;
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}
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function min256(uint256 a, uint256 b) internal pure returns (uint256) {
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return a < b ? a : b;
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}
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}
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