pure.js

var PureComponent = React.createClass({
  shouldComponentUpdate: function(nextProps, nextState) {
    return !equals(this.props.value, nextProps.value);
  },
  render: function() {
    return this.props.children();
  }
});

var pure = function(value, childrenThunk) {
  return PureComponent({value: value}, childrenThunk);
};