SafeMath .add()施加无限气体

Question

当我从Solidity库中使用SafeMath函数时，在混合中得到无限的气体需求(这反映在无法通过的事务中)。

简化示例：

function someFunction() internal view returns (bool) {
    uint256 a = 23;
    uint256 b = 48;
    return (a.add(1) > b);
}

包括SafeMath。

怎么啦？

下面是包含SafeMath的粘贴：

https://pastebin.com/C4FVyBFa

所用版本：

普拉格玛坚实度^0.4.24；

Answer 1

我的意思是，我们真的需要看到导致这个问题的整个合同，这样我们才能发现一些东西。

这里有一个稍微修改过的函数版本(因此它可以从外部调用)，它可以在一个超级基本的契约外壳中正常工作。

// File: zeppelin-solidity/contracts/math/SafeMath.sol

/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {

  /**
  * @dev Multiplies two numbers, throws on overflow.
  */
  function mul(uint256 _a, uint256 _b) internal pure returns (uint256 c) {
    // Gas optimization: this is cheaper than asserting '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;
    }

    c = _a * _b;
    assert(c / _a == _b);
    return c;
  }

  /**
  * @dev Integer division of two numbers, truncating the quotient.
  */
  function div(uint256 _a, uint256 _b) internal pure 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 _a / _b;
  }

  /**
  * @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
  */
  function sub(uint256 _a, uint256 _b) internal pure returns (uint256) {
    assert(_b <= _a);
    return _a - _b;
  }

  /**
  * @dev Adds two numbers, throws on overflow.
  */
  function add(uint256 _a, uint256 _b) internal pure returns (uint256 c) {
    c = _a + _b;
    assert(c >= _a);
    return c;
  }
}

contract Try {

  using SafeMath for uint256;

  function someFunction() public view returns (bool) {
    uint256 a = 23;
    uint256 b = 48;
    return (a.add(1) > b);
  }

}

如预期的那样，它返回false。

我们需要看到一些编译但不按预期工作的东西。

希望能帮上忙。