// 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) | |
#ifndef BOOST_UNITS_STATIC_CONSTANT_HPP | |
#define BOOST_UNITS_STATIC_CONSTANT_HPP | |
#include <boost/units/config.hpp> | |
/// A convenience macro that allows definition of static | |
/// constants in headers in an ODR-safe way. | |
#define BOOST_UNITS_STATIC_CONSTANT(name, type) \ | |
template<bool b> \ | |
struct name##_instance_t \ | |
{ \ | |
static const type instance; \ | |
}; \ | |
\ | |
namespace \ | |
{ \ | |
static const type& name = name##_instance_t<true>::instance; \ | |
} \ | |
\ | |
template<bool b> \ | |
const type name##_instance_t<b>::instance | |
/// A convenience macro for static constants with auto | |
/// type deduction. | |
#if BOOST_UNITS_HAS_TYPEOF | |
#if BOOST_UNITS_HAS_BOOST_TYPEOF | |
#define BOOST_UNITS_AUTO_STATIC_CONSTANT(name, value) \ | |
BOOST_TYPEOF_NESTED_TYPEDEF(name##_nested_t, value) \ | |
BOOST_UNITS_STATIC_CONSTANT(name, name##_nested_t::type) = (value) | |
#elif BOOST_UNITS_HAS_MWERKS_TYPEOF | |
#define BOOST_UNITS_AUTO_STATIC_CONSTANT(name, value) \ | |
BOOST_UNITS_STATIC_CONSTANT(name, __typeof__(value)) = (value) | |
#elif BOOST_UNITS_HAS_GNU_TYPEOF | |
#define BOOST_UNITS_AUTO_STATIC_CONSTANT(name, value) \ | |
BOOST_UNITS_STATIC_CONSTANT(name, typeof(value)) = (value) | |
#endif // BOOST_UNITS_HAS_BOOST_TYPEOF | |
#endif // BOOST_UNITS_HAS_TYPEOF | |
#endif // BOOST_UNITS_STATIC_CONSTANT_HPP |