Gas Optimizations

[code423n4]

Gas

Check whether there's any rewards before storing these state variables : storedAsset and lastReward

https://github.com/fei-protocol/ERC4626/blob/643cd044fac34bcbf64e1c3790a5126fec0dbec1/src/xERC4626.sol#L87

I mentioned to the dev(Joey|Tribe) that newReward will be zero since whatever asset is deposited in the contract would equal to the storedAsset - lastReward(zero if newReward is zero) .He responded that the donations would come directly from the protocol. But since the frequency of such deposits can't be ascertained, it's counterproductive to be saving a zero value to storage (in the event that there are no rewards for users).

Update the state variable as such :

if(newReward≠0){

storedTotalAssets=storedTotalAssets_+lastRewardAmount_;
lastReward=newReward;
}