Boost C++ Libraries

Reducing Compiling Time

If you have ever exported a lot of classes, you know that it takes quite a good time to compile the Boost.Python wrappers. Plus the memory consumption can easily become too high. If this is causing you problems, you can split the class_ definitions in multiple files:

    /* file point.cpp */
    #include <point.h>
    #include <boost/python.hpp>
    
    void export_point()
    {
        class_<point>("point")...;    
    }

    /* file triangle.cpp */
    #include <triangle.h>
    #include <boost/python.hpp>

    void export_triangle()
    {
        class_<triangle>("triangle")...;
    }

Now you create a file main.cpp, which contains the BOOST_PYTHON_MODULE macro, and call the various export functions inside it.

    void export_point();
    void export_triangle();
    
    BOOST_PYTHON_MODULE(_geom)
    {
        export_point();
        export_triangle();
    }

Compiling and linking together all this files produces the same result as the usual approach:

    #include <boost/python.hpp>
    #include <point.h>
    #include <triangle.h>

    BOOST_PYTHON_MODULE(_geom)
    {
        class_<point>("point")...;
        class_<triangle>("triangle")...;
    } 

but the memory is kept under control.

This method is recommended too if you are developing the C++ library and exporting it to Python at the same time: changes in a class will only demand the compilation of a single cpp, instead of the entire wrapper code.

If you're exporting your classes with Pyste, take a look at the --multiple option, that generates the wrappers in various files as demonstrated here.

This method is useful too if you are getting the error message "fatal error C1204:Compiler limit:internal structure overflow" when compiling a large source file, as explained in the FAQ.

Copyright © 2002-2003 David Abrahams
Copyright © 2002-2003 Joel de Guzman

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