[Feature Request]: React Hooks `Equality` **AKA:** `[isEqual]` Callback

[myckhel]

I would like useMemo, useCallback etc. to accepts some arguments that will allow us to handle the equality function for each dependencies, just something similar to react's memo which accepts optional 2nd argument to control the equality check.

Example:

const value = useMemo(
    () => computeSomething(), 
    [decencies[0], decencies[1]], 
    (nextDependency, prevDependency, dependencyIndex) => {
        if(dependencyIndex === 0){
            return nextDependency === prevDependency;
        } else {
            return nextDependency == prevDependency;
        }
    }
);

Or single equality callback

const value = useMemo(
    () => computeSomething(), 
    [decencies[0], decencies[1]], 
    (nextDependency, prevDependency) => {
       return nextDependency === prevDependency;
    }
);

Please could this feature be considered?

[theKashey]

Like the same comparator we have in React.memo function.

[myckhel]

Like the same comparator we have in React.memo function.

Yes exactly!

[gaearon]

Hi, thanks for your suggestion. RFCs should be submitted as pull requests, not issues. I will close this issue but feel free to resubmit in the PR format.