Solidity 0.8.0 Compatibility

[nanaknihal]

parseInt wasn't working for me with 0.8.0, so I modified a bit. This worked for me if you are interested in updating the library:

/**
    * Parse Int
    * 
    * Converts an ASCII string value into an uint as long as the string 
    * its self is a valid unsigned integer
    * 
    * @param _value The ASCII string to be converted to an unsigned integer
    * @return _ret The unsigned value of the ASCII string
    */
    function parseInt(string memory _value) public view returns (uint256 _ret) {
        bytes memory _bytesValue = bytes(_value);
        uint256 j = 1;
        uint256 i = _bytesValue.length-1;
        while(i >= 0) {
            assert(uint8(_bytesValue[i]) >= 48 && uint8(_bytesValue[i]) <= 57);
            _ret += (uint8(_bytesValue[i]) - 48)*j;
            j*=10;
            if(i > 0){i--;}else{break;}
        }
    }

[kartik5578]

I want to contribute to this issue