std::function return value for OryolClassCreator

[pixelherodev]

Far from perfect, but it should increase support for using arguments in the creator.

I tried using e.g. std::bind as a better workaround as well, without success.

[floooh]

I like the GNU version fix, but not the std::function fix :)

Can you give a code example where wrapping in a std::function is needed?

I think a second set of macros would make sense. Basically leave the current OryolClassCreator() as it is, and add another macro OryolClassCreatorStd(), so I can decide case by case whether I want the function pointer or std::function (and this would also not break existing code)

[pixelherodev]

Uh, it's the other way around. It wraps in a std::function now, my change gets rid of that and uses raw function pointers.

[pixelherodev]

Unfortunately, the args capture in

template<typename... ARGS> static Ptr<TYPE>(*Creator(ARGS... args))() {\
  return [args...] { return Create(args...); };\
};

breaks the lambda because the type of the lambda is incompatible with the return type.

[pixelherodev]

...oops?

[floooh]

Yeah sorry for getting the function-ptr / std::function thing mixed up, guess I didn't have my morning coffee yet...

[floooh]

PS: we shouldn't consider std::bind, I still feel the scars (I guess that's why I was switching to std::function and, the easier argument capturing was the reason)... I think it's best if there's an alternative Creator macro which which returns a function pointer but doesn't support args capturing.

[pixelherodev]

Alright. Another important note is that this appears to not work on Emscripten, so it might be best to leave it as std::function and not add a new macro.

[pixelherodev]

Hold on, I take that back. There is a problem occurring on Emscripten, but I'm now pretty sure this wasn't causing it.

[pixelherodev]

Yeah, this wasn't the problem. #322
Turns out the RTTI in Oryol doesn't work properly with dynamic libraries in Emscripten.

[pixelherodev]

On the other hand, this does break the creator for LocalFS on Windows, and I don't even remember why i wanted it.

Going to close this. If I come up with a better solution in the future, I'll let you know