Elegant way to memoize js objects

weakMemoizeOne.js

// allows to memoize function by its first argument
// this is only partial implementation (can be extended to memoize all arguments though)
const weakMemoizeOne = fn =>
{
	const wmap = new WeakMap();
	const wfn = arg =>
	{
		if(!wmap.has(arg))
			wmap.set(arg, fn(arg));
		return wmap.get(arg);
	};
	return wfn;
};