std smart pointers, type checking for Stack and LuaRef and adding free functions as members #46
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The introduction of an additional trait allows to specify how to obtain a container from a raw pointer which allows types that provide that functionality for shared_ptr via shared_from_this to be managed by a shared_ptr.
The is_a function provides an equivalent to the lua_isnumber, lua_isstring etc. functions for registered custom types.
Added the functionality to use free functions with a fitting first parameter as member functions.
for consistency with the Stack::is_a function a is<T> member function has also be added to LuaRef to check for custom types.
The manual now also mentions the possibility of adding free functions with a "this argument" to classes.
the tostring function was using a absolute index instead of -1 which lead to the wrong value being read to a string and potentially resulting in a exception when assigning NULL to std::string.
There was a case where the checkClass (used by Stack::is_a and LuaRef::is) would unbalance the stack.
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Tried out the "Allow free functions as member functions". Works a treat. I'm using it to give some Ogre3d methods some default parameters, without having to bother with them in Lua. Like you mention it makes making a __tostring "method" easier too! |
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This looks like good stuff, should I just merge it? I haven't been actively developing LuaBridge so its a bit cold on my side. |
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I guess it won't hurt to merge them into develop and try them out. I've merged them into my copy of LuaBridge that I'm hacking around for my game engine. So far so good, although I haven't exercised the is_a stuff ;-) |
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@progschj How are you doing your constructor overloads or overload handlers in general. Have you found some way of taking some of the grind out of writing them? You can see my first go at |
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I do them very similar to what you are doing there. I don't think there is much you can do about it. I guess maybe some form of visitor style thing where you switch on like templated argument lists or so. But I think I'll just stick to "handcoding" them. |
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Thanks progschj, think I'll stick to hand writing these too for now - hopefully I wont need to many! :-) |
std smart pointers, type checking for Stack and LuaRef and adding free functions as members
These are various changes/additions I made based on my use cases:
std::/boost::shared_ptr and similar can be used as container via an additional trait (see the manual).
Stack and LuaRef have convenience functions to check for user defined types. I used this to circumvent the lack of overload support (specifically for constructors) by just taking the lua_State and then sorting out the parameter count and types manually which often requires checking if some lua object is of a specific, potentially custom, type.
Adding free functions as class members similar to the mechanism already present for properties. This allows adding dummy functions to do the aforementioned resolution of overloads without changing the C++ class itself. It also allows adding functions like __tostring __add etc. to types that need to be adapted without intrusion.
The changes are (mostly) documented in the Manual.html.
So far these changes worked for me but there might still be issues that just haven't come up in my use cases. Overall I think they are useful and shouldn't mess with backwards compatibility or performance if not used.