ecency-mobile/ios/Pods/boost-for-react-native/boost/units/static_constant.hpp

58 lines
2.3 KiB
C++
Raw Normal View History

// 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