New syntax proposal (type hinting)

I wish have opportunity to set types not only like: function a(): string {} or function b(): ?string {} but also as: function c(): string | int {} or function d(): ?string | ?array {}// all of them should mark that null is accepted. Similar thing is I suppose is in catch{} clause. Of course not only return types can affected but also types in args. And sometime we can think about types of properties and variables however this is rather long distance future. So the first part of this message is could be done in the near future?