# QVM: Quaternions, Vectors, Matrices

### boost/qvm/mat_traits_defaults.hpp

This header defines the mat_traits_defaults template which can be used as a convenient base type for mat_traits specializations.

### Synopsis:

#include <boost/qvm/mat_traits_defaults.hpp>

    namespace boost
    {
        namespace qvm
        {
            template <class MatType,class ScalarType,int Rows,int Cols>
            struct mat_traits_defaults
            {
                typedef MatType mat_type;
                typedef ScalarType scalar_type;
                static int const rows=Rows;
                static int const cols=Cols;

                template <int Row,int Col>
                static BOOST_QVM_INLINE_CRITICAL
                scalar_type write_element( mat_type const & x )
                {
                    return mat_traits<mat_type>::template write_element<Row,Col>(const_cast<mat_type &>(x));
                }

                static BOOST_QVM_INLINE_CRITICAL
                scalar_type read_element_idx( int r, int c, mat_type const & x )
                {
                    return mat_traits<mat_type>::write_element_idx(r,c,const_cast<mat_type &>(x));
                }

                protected:

                static BOOST_QVM_INLINE_TRIVIAL
                scalar_type & write_element_idx( int r, int c, mat_type & m )
                {
                    /* unspecified */
                }
            };
        }
    }

See also: mat_traits_defaults