Gas Optimizations

[code423n4]

i++ CAN BE UNCHECK AND REPLACED WITH ++i

++i costs less gas compared to i++ or i += 1 for unsigned integer, as pre-increment is cheaper (about 5 gas per iteration). This statement is true even with the optimizer enabled.

Besides, In Solidity 0.8+, there’s a default overflow check on unsigned integers. It’s possible to uncheck this in for-loops and save some gas at each iteration, but at the cost of some code readability, as this uncheck cannot be made inline. The risk of overflow is inexistant for a uint256 here.

Original code:
https://github.com/code-423n4/2022-07-fractional/blob/e2c5a962a94106f9495eb96769d7f60f7d5b14c9/src/Vault.sol#L104
https://github.com/code-423n4/2022-07-fractional/blob/e2c5a962a94106f9495eb96769d7f60f7d5b14c9/src/Vault.sol#L78

So the gas optimized code would be

for (uint256 i = 0; i < length;) {    
     //...
    unchecked { ++i; }  
}