useCallback() alternative implementation

[muqg]

useCallback provides a way to memoize callbacks based on whether an array of given values changes. I have been wondering if it could work like something similar to this instead:

function useStatic(cb) {
  const callback = useRef(cb)
  callback.current = cb

  const mem = useRef((...args) => callback.current(...args))
  return mem.current
}

Note that this is just a mock implementation to illustrate my idea. This hook above will always return the same function instance that is kept within the reference object, while always calling the latest version of the callback argument. This way the need to pass props to be compared is omitted which could also be an improvement to its performance.

Here is a side to side usage comparison:

function MyComponent({title}) {
  // Will return the memoized callback if title didn't change.
  const current = useCallback(() => alert(title), [title])

  // Will return a memoized callback, even if title changes,
  // while there is also no need to check if it did change.
  const alternative = useStatic(() => alert(title))
}

[gaearon]

Please see reactjs/rfcs#83 (comment) and #14099. Thanks!

[gaearon]

We've submitted a proposal to solve this. Would appreciate your input!

reactjs/rfcs#220