Is it possible to load a C++ shared library to Mathematica 8.0?

Question

I'm trying to load a C++ function compiled to a shared library from Mathematica 8.0. I did manage to use a C function using MathLink but MathLink does not seem to support C++ functions. So I tried to create a shared library and load it through LibraryLink, but LibraryFunctionLoad does not seem to be able to load a C++ function. Does anyone managed to use a C++ function within Mathematica, and if so, what are the tricks that one have to do to make it work?

Answer 1

The problem is that the C++ code uses mangling of the symbols being exported.

This encodes the namespace, classname, return type, name and parameters as part of the exported symbol. This means that a function called:

int hello(int x, int y, int z)

exports as something like:

_Z5helloiii

This was done on g++ on linux, windows has a different mangling scheme.

In order to ensure that functions are exported in a C compatible way, you wrap the function in the extern "C" mechanism, which causes it to be exported in a form that is compatible with MathLink

so you use the following in the header:

#ifdef __cplusplus
extern "C" {
#endif

int hello(int x, int y, int z);

#ifdef __cplusplus
}
#endif

As long as you #include this header in your C++ implementation, it should link correctly with MathLink