output_static_matrix transformer

Definition

“output_static_matrix” transformer works on native 2D static arrays. It handles the translation between a matrix and Python list object. The matrix row and column sizes should be known in advance.

“output_static_matrix” transformer takes as first argument name or index of the original function argument. The argument should have “array” or “pointer” type. The second and the third arguments specify rows and columns size.

Limitations

This transformer could not be applied on virtual functions.

Example

void filler( int m[2][3], int value ){
    for( int r = 0; r < 2; ++r ){
        for( int c = 0; c < 3; ++c ){
            m[r][c] = value;
        }
    }
}

In order to expose filler function we need to create a small wrapper. The following Py++ code does it for you:

from pyplusplus import module_builder
from pyplusplus import function_transformers as FT

mb = module_builder.module_builder_t( ... )
filler = mb.free_fun( 'filler' )
filler.add_transformation( ft.output_static_matrix('m', rows=2, columns=3) )

What you see below is the relevant pieces of generated code:

#include "__convenience.pypp.hpp" //Py++ header file, which contains few convenience function

namespace bp = boost::python;

static boost::python::object filler_7b0a7cb8f4000f0474aa44d21c2e4917( int value ){
    int native_m[2][3];
    boost::python::list py_m;
    ::ft::filler(native_m, value);
    for (int row = 0; row < 2; ++row ){
        boost::python::list pyrow;
        pyplus_conv::copy_container( native_m[row]
                                     , native_m[row] + 3
                                     , pyplus_conv::list_inserter( pyrow ) );
        py_m.append( pyrow );
    }
    return bp::object( py_m );
}

BOOST_PYTHON_MODULE(...){
    ...
   typedef boost::python::object ( *filler_function_type )( int );

   bp::def(
       "filler"
       , filler_function_type( &filler_7b0a7cb8f4000f0474aa44d21c2e4917 )
       , ( bp::arg("value") ) );
}