Redundant SafeMath Usage

Description

The SafeMath library is often used to prevent integer overflow and underflow issues in Solidity contracts. However, in some cases, the usage of the SafeMath library may not be necessary, and it can result in unnecessary gas consumption.

For example, in Solidity versions prior to 8.0, the add function in the SafeMath library is necessary to prevent integer overflow, but in Solidity 8.0 and later, the built-in overflow protection makes the use of SafeMath unnecessary in many cases.

Example Code

pragma solidity 0.7.5;

import "@openzeppelin/contracts/math/SafeMath.sol";

contract Example {
    using SafeMath for uint256;
    uint256 public totalSupply;

    function mint(uint256 amount) public {
        totalSupply = totalSupply.add(amount);
    }
}

In this example, the add function from the SafeMath library is used to prevent integer overflow when adding the amount parameter to the totalSupply variable. However, in Solidity 8.0 and later, this protection is built in, and the usage of SafeMath in this case is unnecessary.

Recommendation

It is recommended to check the Solidity version being used and determine if SafeMath is necessary in each specific case. In Solidity 8.0 and later, the usage of SafeMath can often be omitted, resulting in decreased gas consumption and simpler code. In Solidity versions prior to 8.0, the usage of SafeMath is often necessary to prevent integer overflow and underflow issues.