boost_1_45_0/libs/units/example/dimension.cpp

// Boost.Units - A C++ library for zero-overhead dimensional analysis and 
// unit/quantity manipulation and conversion
//
// Copyright (C) 2003-2008 Matthias Christian Schabel
// Copyright (C) 2008 Steven Watanabe
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)

/** 
\file
    
\brief dimension.cpp

\details
Test dimension list manipulation.

Output:
@verbatim

//[dimension_output
length_dimension  = list<dim<length_base_dimension, static_rational<1l, 1l> >, dimensionless_type>
mass_dimension    = list<dim<mass_base_dimension, static_rational<1l, 1l> >, dimensionless_type>
time_dimension    = list<dim<time_base_dimension, static_rational<1l, 1l> >, dimensionless_type>
energy_dimension  = list<dim<length_base_dimension, static_rational<2l, 1l> >, list<dim<mass_base_dimension, static_rational<1l, 1l> >, list<dim<time_base_dimension, static_rational<-2l, 1l> >, dimensionless_type> > >
LM_type      = list<dim<length_base_dimension, static_rational<1l, 1l> >, list<dim<mass_base_dimension, static_rational<1l, 1l> >, dimensionless_type> >
L_T_type     = list<dim<length_base_dimension, static_rational<1l, 1l> >, list<dim<time_base_dimension, static_rational<-1l, 1l> >, dimensionless_type> >
V_type       = list<dim<length_base_dimension, static_rational<1l, 1l> >, list<dim<time_base_dimension, static_rational<-1l, 1l> >, dimensionless_type> >
//]

@endverbatim
**/

#include <boost/type_traits/is_same.hpp>
#include <boost/mpl/assert.hpp>

#include <iostream>

#include <boost/units/detail/utility.hpp>

#include "test_system.hpp"

namespace mpl = boost::mpl;

int main(void)
{   
    using namespace boost::units;

    BOOST_MPL_ASSERT((boost::is_same<
        length_dimension,
        mpl::push_front<
            dimensionless_type,
            dim<length_base_dimension, static_rational<1L, 1L> >
        >::type
    >));
    BOOST_MPL_ASSERT((boost::is_same<
        mass_dimension,
        mpl::push_front<
            dimensionless_type,
            dim<mass_base_dimension, static_rational<1L, 1L> >
        >::type
    >));
    BOOST_MPL_ASSERT((boost::is_same<energy_dimension, 
        mpl::push_front<
        mpl::push_front<
        mpl::push_front<
        dimensionless_type,
        dim<time_base_dimension, static_rational<-2L, 1L> > >::type,
        dim<mass_base_dimension, static_rational<1L, 1L> > >::type,
        dim<length_base_dimension, static_rational<2L, 1L> > >::type>));
                              
    std::cout << "length_dimension  = "
              << simplify_typename(length_dimension()) << std::endl
              << "mass_dimension    = "
              << simplify_typename(mass_dimension()) << std::endl
              << "time_dimension    = "
              << simplify_typename(time_dimension()) << std::endl
              << "energy_dimension  = "
              << simplify_typename(energy_dimension()) << std::endl;
                  
    //[dimension_snippet_1
    typedef mpl::times<length_dimension,mass_dimension>::type   LM_type;
    typedef mpl::divides<length_dimension,time_dimension>::type L_T_type;
    typedef static_root<
        mpl::divides<energy_dimension,mass_dimension>::type,
        static_rational<2>
    >::type    V_type;
    //]
    
    BOOST_MPL_ASSERT((boost::is_same<LM_type, 
        mpl::push_front<
        mpl::push_front<
        dimensionless_type,
        dim<mass_base_dimension, static_rational<1L, 1L> > >::type,
        dim<length_base_dimension, static_rational<1L, 1L> > >::type>));

    BOOST_MPL_ASSERT((boost::is_same<L_T_type, 
        mpl::push_front<
        mpl::push_front<
        dimensionless_type,
        dim<time_base_dimension, static_rational<-1L, 1L> > >::type,
        dim<length_base_dimension, static_rational<1L, 1L> > >::type>));

    BOOST_MPL_ASSERT((boost::is_same<V_type, 
        mpl::push_front<
        mpl::push_front<
        dimensionless_type,
        dim<time_base_dimension, static_rational<-1L, 1L> > >::type,
        dim<length_base_dimension, static_rational<1L, 1L> > >::type>));
    
    std::cout << "LM_type      = " << simplify_typename(LM_type()) << std::endl
              << "L_T_type     = " << simplify_typename(L_T_type()) << std::endl
              << "V_type       = " << simplify_typename(V_type()) << std::endl;
              
    return 0;
}