Trotyl Yu

## API https://reactjs.org/docs/react-api.html#reactchildren

## API https://reactjs.org/docs/react-api.html#isvalidelement

## API https://reactjs.org/docs/react-api.html#reactmemo

## API https://reactjs.org/docs/react-api.html#cloneelement

## API https://reactjs.org/docs/react-api.html#reactpurecomponent

## Guide https://reactjs.org/docs/uncontrolled-components.html

## Guide https://reactjs.org/docs/portals.html ## API https://reactjs.org/docs/react-dom.html#createportal

Support `render` function returning `Array`.

## Current All nested `Array`s are flattened to children, would cause problem when having same `key` among different `Array`s, also make diffing take more effort. ## Expected Each nested `Array`...

## Guide https://reactjs.org/docs/refs-and-the-dom.html https://reactjs.org/docs/forwarding-refs.html ## API https://reactjs.org/docs/react-api.html#reactcreateref https://reactjs.org/docs/react-api.html#reactforwardref https://reactjs.org/docs/refs-and-the-dom.html#callback-refs