# QVM: Quaternions, Vectors, Matrices

### quat_traits_defaults

#include <boost/qvm/quat_traits_defaults.hpp>

    namespace boost
    {
        namespace qvm
        {
            template <class QuatType,class ScalarType>
            struct quat_traits_defaults
            {
                typedef QuatType quat_type;
                typedef ScalarType scalar_type;

                template <int I>
                static BOOST_QVM_INLINE_CRITICAL
                scalar_type read_element( quat_type const & x )
                {
                    return quat_traits<quat_type>::template write_element<I>(const_cast<quat_type &>(x));
                }
            };
        }
    }

The quat_traits_defaults template is designed to be used as a public base for user-defined specializations of the quat_traits template, to easily define the required members. If it is used, the only member that must be defined by the user in a quat_traits specialization is write_element; the quat_traits_defaults base will define read_element, as well as scalar_type automatically.

See also: boost/qvm/quat_traits_defaults.hpp