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- // Copyright (C) 2007, 2008 Steven Watanabe, Joseph Gauterin, Niels Dekker
- // Copyright (C) 2023 Andrey Semashev
- //
- // 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)
- // For more information, see http://www.boost.org
- #ifndef BOOST_CORE_INVOKE_SWAP_HPP
- #define BOOST_CORE_INVOKE_SWAP_HPP
- // Note: the implementation of this utility contains various workarounds:
- // - invoke_swap_impl is put outside the boost namespace, to avoid infinite
- // recursion (causing stack overflow) when swapping objects of a primitive
- // type.
- // - std::swap is imported with a using-directive, rather than
- // a using-declaration, because some compilers (including MSVC 7.1,
- // Borland 5.9.3, and Intel 8.1) don't do argument-dependent lookup
- // when it has a using-declaration instead.
- // - The main entry function is called invoke_swap rather than swap
- // to avoid forming an infinite recursion when the arguments are not
- // swappable.
- #include <boost/core/enable_if.hpp>
- #include <boost/config.hpp>
- #if __cplusplus >= 201103L || defined(BOOST_DINKUMWARE_STDLIB)
- #include <utility> // for std::swap (C++11)
- #else
- #include <algorithm> // for std::swap (C++98)
- #endif
- #include <cstddef> // for std::size_t
- #ifdef BOOST_HAS_PRAGMA_ONCE
- #pragma once
- #endif
- #if defined(BOOST_GCC) && (BOOST_GCC < 40700)
- // gcc 4.6 ICEs on noexcept specifications below
- #define BOOST_CORE_SWAP_NOEXCEPT_IF(x)
- #else
- #define BOOST_CORE_SWAP_NOEXCEPT_IF(x) BOOST_NOEXCEPT_IF(x)
- #endif
- namespace boost_swap_impl {
- // we can't use type_traits here
- template<class T> struct is_const { enum _vt { value = 0 }; };
- template<class T> struct is_const<T const> { enum _vt { value = 1 }; };
- // Use std::swap if argument dependent lookup fails.
- // We need to have this at namespace scope to be able to use unqualified swap() call
- // in noexcept specification.
- using namespace std;
- template<class T>
- BOOST_GPU_ENABLED
- inline void invoke_swap_impl(T& left, T& right) BOOST_CORE_SWAP_NOEXCEPT_IF(BOOST_NOEXCEPT_EXPR(swap(left, right)))
- {
- swap(left, right);
- }
- template<class T, std::size_t N>
- BOOST_GPU_ENABLED
- inline void invoke_swap_impl(T (& left)[N], T (& right)[N])
- BOOST_CORE_SWAP_NOEXCEPT_IF(BOOST_NOEXCEPT_EXPR(::boost_swap_impl::invoke_swap_impl(left[0], right[0])))
- {
- for (std::size_t i = 0; i < N; ++i)
- {
- ::boost_swap_impl::invoke_swap_impl(left[i], right[i]);
- }
- }
- } // namespace boost_swap_impl
- namespace boost {
- namespace core {
- template<class T>
- BOOST_GPU_ENABLED
- inline typename enable_if_c< !::boost_swap_impl::is_const<T>::value >::type
- invoke_swap(T& left, T& right)
- BOOST_CORE_SWAP_NOEXCEPT_IF(BOOST_NOEXCEPT_EXPR(::boost_swap_impl::invoke_swap_impl(left, right)))
- {
- ::boost_swap_impl::invoke_swap_impl(left, right);
- }
- } // namespace core
- } // namespace boost
- #undef BOOST_CORE_SWAP_NOEXCEPT_IF
- #endif // BOOST_CORE_INVOKE_SWAP_HPP
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