129 lines
4.1 KiB
Plaintext
129 lines
4.1 KiB
Plaintext
|
// 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) 2007-2008 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 base unit (meter, kg, sec...).
|
||
|
|
/// \details base unit definition registration.
|
||
|
|
|
||
|
|
#ifndef BOOST_UNITS_BASE_UNIT_HPP
|
||
|
|
#define BOOST_UNITS_BASE_UNIT_HPP
|
||
|
|
|
||
|
|
#include <boost/units/config.hpp>
|
||
|
|
#include <boost/units/heterogeneous_system.hpp>
|
||
|
|
#include <boost/units/static_rational.hpp>
|
||
|
|
#include <boost/units/units_fwd.hpp>
|
||
|
|
#include <boost/units/unit.hpp>
|
||
|
|
#include <boost/units/detail/dimension_list.hpp>
|
||
|
|
#include <boost/units/detail/ordinal.hpp>
|
||
|
|
#include <boost/units/detail/prevent_redefinition.hpp>
|
||
|
|
|
||
|
|
namespace boost {
|
||
|
|
|
||
|
|
namespace units {
|
||
|
|
|
||
|
|
/// This must be in namespace boost::units so that ADL
|
||
|
|
/// will work with friend functions defined inline.
|
||
|
|
/// Base dimensions and base units are independent.
|
||
|
|
/// INTERNAL ONLY
|
||
|
|
template<long N> struct base_unit_ordinal { };
|
||
|
|
|
||
|
|
/// INTERNAL ONLY
|
||
|
|
template<class T, long N> struct base_unit_pair { };
|
||
|
|
|
||
|
|
/// INTERNAL ONLY
|
||
|
|
template<class T, long N>
|
||
|
|
struct check_base_unit {
|
||
|
|
enum {
|
||
|
|
value =
|
||
|
|
sizeof(boost_units_unit_is_registered(units::base_unit_ordinal<N>())) == sizeof(detail::yes) &&
|
||
|
|
sizeof(boost_units_unit_is_registered(units::base_unit_pair<T, N>())) != sizeof(detail::yes)
|
||
|
|
};
|
||
|
|
};
|
||
|
|
|
||
|
|
/// Defines a base unit. To define a unit you need to provide
|
||
|
|
/// the derived class (CRTP), a dimension list and a unique integer.
|
||
|
|
/// @code
|
||
|
|
/// struct my_unit : boost::units::base_unit<my_unit, length_dimension, 1> {};
|
||
|
|
/// @endcode
|
||
|
|
/// It is designed so that you will get an error message if you try
|
||
|
|
/// to use the same value in multiple definitions.
|
||
|
|
template<class Derived,
|
||
|
|
class Dim,
|
||
|
|
long N
|
||
|
|
#if !defined(BOOST_UNITS_DOXYGEN) && !defined(__BORLANDC__)
|
||
|
|
,
|
||
|
|
class = typename detail::ordinal_has_already_been_defined<
|
||
|
|
check_base_unit<Derived, N>::value
|
||
|
|
>::type
|
||
|
|
#endif
|
||
|
|
>
|
||
|
|
class base_unit :
|
||
|
|
public ordinal<N>
|
||
|
|
{
|
||
|
|
public:
|
||
|
|
/// INTERNAL ONLY
|
||
|
|
typedef void boost_units_is_base_unit_type;
|
||
|
|
/// INTERNAL ONLY
|
||
|
|
typedef base_unit this_type;
|
||
|
|
/// The dimensions of this base unit.
|
||
|
|
typedef Dim dimension_type;
|
||
|
|
|
||
|
|
/// Provided for mpl compatability.
|
||
|
|
typedef Derived type;
|
||
|
|
|
||
|
|
/// The unit corresponding to this base unit.
|
||
|
|
#ifndef BOOST_UNITS_DOXYGEN
|
||
|
|
typedef unit<
|
||
|
|
Dim,
|
||
|
|
heterogeneous_system<
|
||
|
|
heterogeneous_system_impl<
|
||
|
|
list<
|
||
|
|
heterogeneous_system_dim<Derived,static_rational<1> >,
|
||
|
|
dimensionless_type
|
||
|
|
>,
|
||
|
|
Dim,
|
||
|
|
no_scale
|
||
|
|
>
|
||
|
|
>
|
||
|
|
> unit_type;
|
||
|
|
#else
|
||
|
|
typedef detail::unspecified unit_type;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
private:
|
||
|
|
/// Check for C++0x. In C++0x, we have to have identical
|
||
|
|
/// arguments but a different return type to trigger an
|
||
|
|
/// error. Note that this is only needed for clang as
|
||
|
|
/// check_base_unit will trigger an error earlier
|
||
|
|
/// for compilers with less strict name lookup.
|
||
|
|
/// INTERNAL ONLY
|
||
|
|
friend Derived*
|
||
|
|
check_double_register(const units::base_unit_ordinal<N>&)
|
||
|
|
{ return(0); }
|
||
|
|
|
||
|
|
/// Register this ordinal
|
||
|
|
/// INTERNAL ONLY
|
||
|
|
friend detail::yes
|
||
|
|
boost_units_unit_is_registered(const units::base_unit_ordinal<N>&)
|
||
|
|
{ detail::yes result; return(result); }
|
||
|
|
|
||
|
|
/// But make sure we can identify the current instantiation!
|
||
|
|
/// INTERNAL ONLY
|
||
|
|
friend detail::yes
|
||
|
|
boost_units_unit_is_registered(const units::base_unit_pair<Derived, N>&)
|
||
|
|
{ detail::yes result; return(result); }
|
||
|
|
};
|
||
|
|
|
||
|
|
} // namespace units
|
||
|
|
|
||
|
|
} // namespace boost
|
||
|
|
|
||
|
|
#endif // BOOST_UNITS_BASE_UNIT_HPP
|