function / method by macro

[Pangamini]

Hi there.
Do you think it is possible (in visual c++) to use some macro to define a function / method and register it somewhere at the same time? Like:

Code: Select all

LUAAPI int SetMaxForce(float force)
{
...
}

the LUAAPI macro would define a function like normal, but parse its header definition and create an object - so the result from preprocessor and above code would be like:

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int SetMinMaxForce(float maxforce, float minforce)
{
....
}

ApiRegistrator( TYPE_INT,  &SetMaxForce, TYPE_FLOAT, TYPE_FLOAT);

[Pangamini]

Or even better

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int SetMinMaxForce(float maxforce, float minforce)
{
....
}

ApiRegistrator( TYPE_INT, "SetMinMaxForce"  &SetMaxForce, TYPE_FLOAT, "maxforce", TYPE_FLOAT, "minforce");

[madmarx]

It's possible to do something like :

DeclareFunction(int,SetMinMaxForce,floa,maxforce,float,minforce)
{
....
}

which will generate :

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int SetMinMaxForce(float maxforce, float minforce);
ApiRegistrator( TYPE_INT, "SetMinMaxForce"  &SetMaxForce, TYPE_FLOAT, "maxforce", TYPE_FLOAT, "minforce");

int SetMinMaxForce(float maxforce, float minforce);
{
....
}

But it won't work if you got comma in your types (like std::map<int,int>). So another one that is available is :

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DeclareFunction((int)(SetMinMaxForce)(float)(maxforce)(float)(minforce))
{
....
}

I already did one like this once.

But before you got further here are 2 other potential ways of doing it.
A/ use your own code parser/generator. In that case, what you proposed becomes completely doable, and more readable/maintainable.
B/ use boost to extract the function characteristics. So you just need to get the function name as input, and everything else can be generated. I think boost::function + boost::fusion should be able to do it well. Have a look at how ChaiScript works (in its c++ side, when you declare function), because I think it can do just that.

[Pangamini]

Thanks for reply. I don't know though, how to use "your own code parser / generator". It's like writing your own preprocessor or some layer in it? Do i have to use some tools like cmake, or can i do this in visual studio?

[madmarx]

Basically, you read the file yourself, and parse it as a string and then generate the .h or .cpp.
Personnaly i use "boost.spirit" to do the parsing stuff into a struct representing an header file, and then I generate the output manually (edit : I mean "without using spirit auto generator code", but my own generator from the struct).

[Pangamini]

I discovered LuaBind... not exactly the solution for the given, but it does prety much what i wanted and even more!