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Add documentation to safemath functions

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Fixes #655
This commit is contained in:
Santiago Palladino
2018-01-11 11:11:43 -03:00
parent 94697726f5
commit 21297e2b2c
1 changed files with 13 additions and 0 deletions
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13
contracts/math/SafeMath.sol
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@ -6,6 +6,10 @@ pragma solidity ^0.4.18;
* @dev Math operations with safety checks that throw on error * @dev Math operations with safety checks that throw on error
*/ */
library SafeMath { library SafeMath {
/**
* @dev Multiplies two numbers, throws on overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) { function mul(uint256 a, uint256 b) internal pure returns (uint256) {
if (a == 0) { if (a == 0) {
return 0; return 0;
@ -15,6 +19,9 @@ library SafeMath {
return c; return c;
} }
/**
* @dev Integer division of two numbers, truncating the quotient.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) { function div(uint256 a, uint256 b) internal pure returns (uint256) {
// assert(b > 0); // Solidity automatically throws when dividing by 0 // assert(b > 0); // Solidity automatically throws when dividing by 0
uint256 c = a / b; uint256 c = a / b;
@ -22,11 +29,17 @@ library SafeMath {
return c; return c;
} }
/**
* @dev Substracts two numbers, throws if subtrahend is greater than minuend.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) { function sub(uint256 a, uint256 b) internal pure returns (uint256) {
assert(b <= a); assert(b <= a);
return a - b; return a - b;
} }
/**
* @dev Adds two numbers, throws on overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) { function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b; uint256 c = a + b;
assert(c >= a); assert(c >= a);