A WeakMap which accepts multiple objects as a key
npm install weaktuplemapWeakTupleMap    
============
A WeakMap which accepts multiple objects as a key.
This lib is one of the several possible cache for memoize-immutable,
but it can suit other use-cases as it implements a usual Map API.
npm install --save WeakTupleMap
This lib has no dependency, but requires a native implementation of WeakMap.
Restrictions. A WeakTupleMap can only be used when:
- The key is only made of parts that have a non-primitive type
(object, array, or function).
- The key always has the same number of parts.
``js
var WeakTupleMap = require('WeakTupleMap');
var cache = new WeakTupleMap();
var keyPart1 = {};
var keyPart2 = function() { return 'yolo'; };
var keyPart3 = [];
var value = {any: 'thing'};
// Note that following keyPart tuples are wrapped in new arrays that are !==
// (otherwise a WeakMap would have been enough).
cache.set([keyPart1, keyPart2, keyPart3], value);
cache.has([keyPart1, keyPart2, keyPart3]) === true;
cache.get([keyPart1, keyPart2, keyPart3]) === value;
``
MPL-2.0