// "SPDX-License-Identifier: Apache-2.0"
pragma solidity ^0.6.11;


/**
 * @title SafeMathUint
 * @dev Math operations with safety checks that revert on error
 */
library SafeMathUint {
    function toInt256Safe(uint256 a) internal pure returns (int256) {
        int256 b = int256(a);

        require(b >= 0);

        return b;
    }
}