// 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>
|
|
#if defined(BOOST_NO_CXX11_CONSTEXPR) || defined(BOOST_UNITS_DOXYGEN)
|
/// 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
|
#else
|
# define BOOST_UNITS_STATIC_CONSTANT(name, type) \
|
BOOST_STATIC_CONSTEXPR type name
|
#endif
|
|
/// 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
|
