Gas Optimizations

[code423n4]

1. Use Custom Error instead of Revert String to Save Gas

Custom error from solidity 0.8.4 are cheaper than revert strings, custom error are defined using the error statement can use inside and outside the contract.

source https://blog.soliditylang.org/2021/04/21/custom-errors/

i suggest replacing revert error strings with custom error

POC :

https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/factories/PairFactory.sol#L56 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/factories/PairFactory.sol#L61 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/factories/PairFactory.sol#L66 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/factories/PairFactory.sol#L67 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/factories/PairFactory.sol#L69 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/factories/PairFactory.sol#L89 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/factories/PairFactory.sol#L91 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/factories/PairFactory.sol#L92 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Router.sol#L25 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Router.sol#L40 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Router.sol#L42 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Router.sol#L58 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Router.sol#L59 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Router.sol#L87 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Router.sol#L177 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Router.sol#L182 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Router.sol#L249 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Router.sol#L250 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Router.sol#L341 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Router.sol#L356 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Router.sol#L369 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Router.sol#L371 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Router.sol#L382 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Router.sol#L384 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Router.sol#L406 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L163 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L307 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L773 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L774 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L786 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L787 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L820 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L821 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L834 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L835 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L836 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L837 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L846 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L849 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L1085 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L1245 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L1315 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L1378 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L1382 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/VotingEscrow.sol#L1386 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Pair.sol#L303 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Pair.sol#L322 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Pair.sol#L336 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Pair.sol#L338 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Pair.sol#L344 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Pair.sol#L353 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Pair.sol#L361 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Pair.sol#L467 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Pair.sol#L485 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Minter.sol#L65 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Minter.sol#L70 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Minter.sol#L75 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Minter.sol#L76 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Gauge.sol#L615 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Gauge.sol#L627 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Gauge.sol#L635 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Gauge.sol#L642 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Bribe.sol#L31 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Bribe.sol#L44 https://github.com/code-423n4/2022-05-velodrome/blob/main/contracts/contracts/Bribe.sol#L69

[pooltypes]

Duplicate of #69

[GalloDaSballo]

In lack of gas golfing I can't give the report any points