Support 'pragma unchecked' in Solidity 0.8.0

[mudgen]

I have a style of dealing with over/underflows in Solidity that works like this:

Very often I use large enough variables in contexts where it is impossible to overflow and/or underflow them. Therefore I don't need to use SafeMath or default reverts from Solidity 0.8.0.

In cases where using large enough variables to prevent overflow/underflow is not possible I use explicit require statements or other custom logic to handle. I found that doing this better expresses the algorithm being implemented and can give better error messages.

I have found it important to be aware of and understand each mathematical operation that occurs in a contract and if it can over/underflow and the consequences if that happens and handle accordingly. Reverting on under/overflow is not always the right action and can result in locking funds in contracts forever. So it is important to be aware of and understand each potential over/underflow and handle it correctly.

With this style the default revert on under/overflow from Solidity 0.8.0 is not used and requires me to run all my mathematical operations within unchecked blocks. I would like to request a pragma unchecked or similar directive that turns off default reverts on over/underflow for the whole file.

Besides supporting the style I mention above the pragma could make it easier and faster to port older Solidity code to Solidity 0.8.0.

[ajb]

Please, please, please implement this feature.

[MerlinEgalite]

Would be awesome yes!

[github-actions]

This issue has been marked as stale due to inactivity for the last 90 days.
It will be automatically closed in 7 days.

[github-actions]

Hi everyone! This issue has been automatically closed due to inactivity.
If you think this issue is still relevant in the latest Solidity version and you have something to contribute, feel free to reopen.
However, unless the issue is a concrete proposal that can be implemented, we recommend starting a language discussion on the forum instead.