Submission Details
Severity:
Gas Optimization: Unchecked can be applied to the increment of boxesOwned
Summary
Since it is unlikely to cause overflows, buyBox can make use of unchecked and ++ operator to save on gas costs, since it is unlikely that enough boxes will be accumulated to cause an overflow and the implicit overflow check costs unnecessary gas.
Vulnerability Details
Unnecessary costs due to implicit overflow check of solidity
function buyBox() public payable {
require(msg.value == boxPrice, "Incorrect ETH sent");
boxesOwned[msg.sender] += 1; //-> unchecked {++boxesOwned[msg.sender]}
}
Impact
Gas waste
Tools Used
Manual Review
Recommendation
Add an unchecked block that covers boxesOvned and ++ operator for the incrementor to save gas costs
Rewards breakdown
nSLOC
86This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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