Added function to retrieve all the resources<T> from the ResourceManager

[roig]

Hello mosra, I need that feature. #363

Let's discuss how to implement it 😄 I added a getAll function. Should I go with tests or do you want that feature implemented in another way?

[mosra]

Hi, sorry, being busy with other things. How fast you need that?

I think the best way to go about this is exposing a resources<T>() that returns something that can be iterated through (so, having a begin()/end()), as that's better than forcing the users into a std::vector and is also allocation-free. I have a sketch in mind, but won't be able to get to it until much later today (but more likely tomorrow) -- in the meantime, can you live with the code you have right now?

[roig]

Yes of course. In the meantime I will try to implement it myself.

[roig]

woah.. I don't have the knowledge to do this.. sorry. I will wait your implementation. 😢

I started a class Resources with begin and end methods that will return a ResourceIterator. But don't know exactly how to retrieve iterators from Implementation::ResourceManagerData.