You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
35 lines
846 B
35 lines
846 B
pragma solidity ^0.4.11;
|
|
|
|
|
|
/**
|
|
* @title SafeMath
|
|
* @dev Math operations with safety checks that throw on error
|
|
*/
|
|
library SafeMath {
|
|
function mul(uint256 a, uint256 b) internal constant returns (uint256) {
|
|
if (a == 0) {
|
|
return 0;
|
|
}
|
|
uint256 c = a * b;
|
|
assert(c / a == b);
|
|
return c;
|
|
}
|
|
|
|
function div(uint256 a, uint256 b) internal constant returns (uint256) {
|
|
// assert(b > 0); // Solidity automatically throws when dividing by 0
|
|
uint256 c = a / b;
|
|
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
|
|
return c;
|
|
}
|
|
|
|
function sub(uint256 a, uint256 b) internal constant returns (uint256) {
|
|
assert(b <= a);
|
|
return a - b;
|
|
}
|
|
|
|
function add(uint256 a, uint256 b) internal constant returns (uint256) {
|
|
uint256 c = a + b;
|
|
assert(c >= a);
|
|
return c;
|
|
}
|
|
}
|
|
|