Function useContext

docs/external/js/react.development.js:1558–1580

(Context, unstable_observedBits)

  }

  function useContext(Context, unstable_observedBits) {
    var dispatcher = resolveDispatcher();

    {
      if (unstable_observedBits !== undefined) {
        error('useContext() second argument is reserved for future ' + 'use in React. Passing it is not supported. ' + 'You passed: %s.%s', unstable_observedBits, typeof unstable_observedBits === 'number' && Array.isArray(arguments[2]) ? '\n\nDid you call array.map(useContext)? ' + 'Calling Hooks inside a loop is not supported. ' + 'Learn more at https://fb.me/rules-of-hooks' : '');
      } // TODO: add a more generic warning for invalid values.


      if (Context._context !== undefined) {
        var realContext = Context._context; // Don't deduplicate because this legitimately causes bugs
        // and nobody should be using this in existing code.

        if (realContext.Consumer === Context) {
          error('Calling useContext(Context.Consumer) is not supported, may cause bugs, and will be ' + 'removed in a future major release. Did you mean to call useContext(Context) instead?');
        } else if (realContext.Provider === Context) {
          error('Calling useContext(Context.Provider) is not supported. ' + 'Did you mean to call useContext(Context) instead?');
        }
      }
    }

    return dispatcher.useContext(Context, unstable_observedBits);
  }
  function useState(initialState) {
    var dispatcher = resolveDispatcher();
    return dispatcher.useState(initialState);