1 2 // Copyright (C) 2008-2016 Daniel James. 3 // Distributed under the Boost Software License, Version 1.0. (See accompanying 4 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 5 6 #ifndef BOOST_UNORDERED_FWD_HPP_INCLUDED 7 #define BOOST_UNORDERED_FWD_HPP_INCLUDED 8 9 #include <boost/config.hpp> 10 #if defined(BOOST_HAS_PRAGMA_ONCE) 11 #pragma once 12 #endif 13 14 #include <boost/predef.h> 15 16 #if defined(BOOST_UNORDERED_HAVE_PIECEWISE_CONSTRUCT) 17 // Already defined. 18 #elif defined(BOOST_LIBSTDCXX11) 19 // https://github.com/gcc-mirror/gcc/blob/gcc-4_6-branch/libstdc++-v3/include/bits/stl_pair.h#L70 20 #if BOOST_LIBSTDCXX_VERSION > 40600 21 #define BOOST_UNORDERED_HAVE_PIECEWISE_CONSTRUCT 1 22 #endif 23 #elif BOOST_LIB_STD_CXX 24 // https://github.com/llvm-mirror/libcxx/blob/release_30/include/utility#L206 25 #if BOOST_LIB_STD_CXX >= BOOST_VERSION_NUMBER(3, 0, 0) 26 #define BOOST_UNORDERED_HAVE_PIECEWISE_CONSTRUCT 1 27 #endif 28 #elif defined(BOOST_LIB_STD_DINKUMWARE) 29 // Apparently C++11 standard supported in Visual Studio 2012 30 // https://msdn.microsoft.com/en-us/library/hh567368.aspx#stl 31 // 2012 = VC+11 = BOOST_MSVC 1700 Hopefully! 32 // I have no idea when Dinkumware added it, probably a lot 33 // earlier than this check. 34 #if BOOST_LIB_STD_DINKUMWARE >= BOOST_VERSION_NUMBER(6, 50, 0) || \ 35 BOOST_COMP_MSVC >= BOOST_VERSION_NUMBER(17, 0, 0) 36 #define BOOST_UNORDERED_HAVE_PIECEWISE_CONSTRUCT 1 37 #endif 38 #endif 39 40 // Assume that an unknown library does not support piecewise construction. 41 #if !defined(BOOST_UNORDERED_HAVE_PIECEWISE_CONSTRUCT) 42 #define BOOST_UNORDERED_HAVE_PIECEWISE_CONSTRUCT 0 43 #endif 44 45 #if BOOST_UNORDERED_HAVE_PIECEWISE_CONSTRUCT 46 #include <utility> 47 #endif 48 49 namespace boost { 50 namespace unordered { 51 #if BOOST_UNORDERED_HAVE_PIECEWISE_CONSTRUCT 52 using std::piecewise_construct_t; 53 using std::piecewise_construct; 54 #else 55 struct piecewise_construct_t 56 { 57 }; 58 const piecewise_construct_t piecewise_construct = piecewise_construct_t(); 59 #endif 60 } 61 } 62 63 #endif 64