* pure
A higher-order component version of the `React.PureComponent` class.
During an update, the previous props are compared to the new props. If
they are the same, React will skip rendering the component and
its children.
Unlike userspace implementations, `pure` will not add an additional
fiber to the tree.
The first argument must be a functional component; it does not work
with classes.
`pure` uses shallow comparison by default, like `React.PureComponent`.
A custom comparison can be passed as the second argument.
Co-authored-by: Andrew Clark <acdlite@fb.com>
Co-authored-by: Sophie Alpert <sophiebits@fb.com>
* Warn if first argument is not a functional component