1 /* Copyright 2003-2020 Joaquin M Lopez Munoz.
2  * Distributed under the Boost Software License, Version 1.0.
3  * (See accompanying file LICENSE_1_0.txt or copy at
4  * http://www.boost.org/LICENSE_1_0.txt)
5  *
6  * See http://www.boost.org/libs/multi_index for library home page.
7  */
8 
9 #include <boost/config.hpp>
10 
11 #if !defined(BOOST_MULTI_INDEX_DETAIL_UNDEF_IF_CONSTEXPR_MACRO)
12 
13 #if !defined(BOOST_NO_CXX17_IF_CONSTEXPR)
14 #define BOOST_MULTI_INDEX_IF_CONSTEXPR if constexpr
15 #else
16 #define BOOST_MULTI_INDEX_IF_CONSTEXPR if
17 #if defined(BOOST_MSVC)
18 #define BOOST_MULTI_INDEX_DETAIL_C4127_DISABLED
19 #pragma warning(push)
20 #pragma warning(disable:4127) /* conditional expression is constant */
21 #endif
22 #endif
23 
24 #else
25 
26 #undef BOOST_MULTI_INDEX_IF_CONSTEXPR
27 #if defined(BOOST_MULTI_INDEX_DETAIL_C4127_DISABLED)
28 #pragma warning(pop)
29 #undef BOOST_MULTI_INDEX_DETAIL_C4127_DISABLED
30 #endif
31 
32 #endif
33