kangax/compat-table — pull request #208 by webbedspace (2014-08-18 07:39:25+00:00)
Title: Added note to WeakMap and WeakSet results

WeakMap and WeakSet constructor arguments, such as `new WeakSet([obj1, obj2])`, are not supported in most browser platforms. (Chrome 39 (canary) fixes this). This technically doesn't impede the WeakMap functionality, so those browsers retain their "Yes" results.