1// Copyright (C) 2007, 2008 Steven Watanabe, Joseph Gauterin, Niels Dekker
2//
3// Distributed under the Boost Software License, Version 1.0. (See
4// accompanying file LICENSE_1_0.txt or copy at
5// http://www.boost.org/LICENSE_1_0.txt)
6// For more information, see http://www.boost.org
7
8
9#ifndef BOOST_CORE_SWAP_HPP
10#define BOOST_CORE_SWAP_HPP
11
12// Note: the implementation of this utility contains various workarounds:
13// - swap_impl is put outside the boost namespace, to avoid infinite
14// recursion (causing stack overflow) when swapping objects of a primitive
15// type.
16// - swap_impl has a using-directive, rather than a using-declaration,
17// because some compilers (including MSVC 7.1, Borland 5.9.3, and
18// Intel 8.1) don't do argument-dependent lookup when it has a
19// using-declaration instead.
20// - boost::swap has two template arguments, instead of one, to
21// avoid ambiguity when swapping objects of a Boost type that does
22// not have its own boost::swap overload.
23
24#include <utility> //for std::swap (C++11)
25#include <algorithm> //for std::swap (C++98)
26#include <cstddef> //for std::size_t
27#include <boost/config.hpp>
28
29namespace boost_swap_impl
30{
31 template<class T>
32 BOOST_GPU_ENABLED
33 void swap_impl(T& left, T& right)
34 {
35 using namespace std;//use std::swap if argument dependent lookup fails
36 swap(left,right);
37 }
38
39 template<class T, std::size_t N>
40 BOOST_GPU_ENABLED
41 void swap_impl(T (& left)[N], T (& right)[N])
42 {
43 for (std::size_t i = 0; i < N; ++i)
44 {
45 ::boost_swap_impl::swap_impl(left[i], right[i]);
46 }
47 }
48}
49
50namespace boost
51{
52 template<class T1, class T2>
53 BOOST_GPU_ENABLED
54 void swap(T1& left, T2& right)
55 {
56 ::boost_swap_impl::swap_impl(left, right);
57 }
58}
59
60#endif
61