align/detail/integral_constant.hpp

0001 /*
0002 Copyright 2014-2016 Glen Joseph Fernandes
0003 (glenjofe@gmail.com)
0004
0005 Distributed under the Boost Software License, Version 1.0.
0006 (http://www.boost.org/LICENSE_1_0.txt)
0007 */
0008 #ifndef BOOST_ALIGN_DETAIL_INTEGRAL_CONSTANT_HPP
0009 #define BOOST_ALIGN_DETAIL_INTEGRAL_CONSTANT_HPP
0010
0011 #include <boost/config.hpp>
0012
0013 #if !defined(BOOST_NO_CXX11_HDR_TYPE_TRAITS)
0014 #include <type_traits>
0015 #endif
0016
0017 namespace boost {
0018 namespace alignment {
0019 namespace detail {
0020
0021 #if !defined(BOOST_NO_CXX11_HDR_TYPE_TRAITS)
0022 using std::integral_constant;
0023 using std::true_type;
0024 using std::false_type;
0025 #else
0026 template<class T, T Value>
0027 struct integral_constant {
0028     typedef T value_type;
0029     typedef integral_constant type;
0030
0031     BOOST_CONSTEXPR operator value_type() const BOOST_NOEXCEPT {
0032         return Value;
0033     }
0034
0035     BOOST_CONSTEXPR value_type operator()() const BOOST_NOEXCEPT {
0036         return Value;
0037     }
0038
0039     BOOST_STATIC_CONSTEXPR T value = Value;
0040 };
0041
0042 template<class T, T Value>
0043 BOOST_CONSTEXPR_OR_CONST T integral_constant<T, Value>::value;
0044
0045 typedef integral_constant<bool, true> true_type;
0046 typedef integral_constant<bool, false> false_type;
0047 #endif
0048
0049 } /* detail */
0050 } /* alignment */
0051 } /* boost */
0052
0053 #endif