"> 0" is less efficient than "!= 0" for unsigned integers

[code423n4]

Handle

solgryn

Vulnerability details

Impact

You can save gas.

Proof of Concept

"> 0" is used in the following locations:

https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/Vault.sol#L154 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/Vault.sol#L187 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/Vault.sol#L220 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/Vault.sol#L347 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/Vault.sol#L388 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/Vault.sol#L406 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/Vault.sol#L473

https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/CDSTemplate.sol#L100 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/CDSTemplate.sol#L132 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/CDSTemplate.sol#L140 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/CDSTemplate.sol#L142 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/CDSTemplate.sol#L191 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/CDSTemplate.sol#L223 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/CDSTemplate.sol#L296

https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/IndexTemplate.sol#L133 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/IndexTemplate.sol#L166 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/IndexTemplate.sol#L172 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/IndexTemplate.sol#L174 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/IndexTemplate.sol#L199 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/IndexTemplate.sol#L231 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/IndexTemplate.sol#L246 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/IndexTemplate.sol#L274 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/IndexTemplate.sol#L283 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/IndexTemplate.sol#L427 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/IndexTemplate.sol#L477 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/IndexTemplate.sol#L493 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/IndexTemplate.sol#L513 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/IndexTemplate.sol#L612 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/IndexTemplate.sol#L656

https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/Factory.sol#L175 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/Factory.sol#L185 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/Factory.sol#L187

https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L185 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L218 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L237 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L263 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L282 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L321 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L391 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L396 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L401 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L437 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L444 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L521 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L672 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L706 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L726 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L745 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L802 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L804 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L835 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L847 https://github.com/code-423n4/2022-01-insure/blob/19d1a7819fe7ce795e6d4814e7ddf8b8e1323df3/contracts/PoolTemplate.sol#L929

Recommended Mitigation Steps

Change "> 0" to "!=0" for small gas savings.

If you want to automate the work you can run:

$ sed -i 's/> 0/!= 0/g' contracts/*.sol

[0xean]

dupe of #36