use openzeppelin/contracts

Author: 0x-stan

basic/26-quadratic-vote&gitcoin/contracts/FinancingTool.sol

@@ -1,5 +1,8 @@
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
+import "@openzeppelin/contracts/utils/math/SafeMath.sol";
+
 interface IERC20 {
 
     function balanceOf(address account) external view returns (uint256);
@@ -14,51 +17,6 @@ interface IERC20 {
 
 }
 
-library SafeMath {
-    function add(uint256 a, uint256 b) internal pure returns (uint256) {
-        uint256 c = a + b;
-        require(c >= a, "SafeMath: addition overflow");
-
-        return c;
-    }
-
-    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
-        require(b <= a, "SafeMath: subtraction overflow");
-        uint256 c = a - b;
-
-        return c;
-    }
-
-    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
-        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
-        // benefit is lost if 'b' is also tested.
-        // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
-        if (a == 0) {
-            return 0;
-        }
-
-        uint256 c = a * b;
-        require(c / a == b, "SafeMath: multiplication overflow");
-
-        return c;
-    }
-
-    function div(uint256 a, uint256 b) internal pure returns (uint256) {
-        // Solidity only automatically asserts when dividing by 0
-        require(b > 0, "SafeMath: division by zero");
-        uint256 c = a / b;
-        // assert(a == b * c + a % b); // There is no case in which this doesn't hold
-
-        return c;
-    }
-
-    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
-        require(b != 0, "SafeMath: modulo by zero");
-        return a % b;
-    }
-
-}
-
 contract FinancingTool {
     function safeTransfer(address token, address to, uint256 value) internal {
         (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0xa9059cbb, to, value));