// Copyright (C) 2007, 2008 Steven Watanabe, Joseph Gauterin, Niels Dekker // // 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_UTILITY_SWAP_HPP #define BOOST_UTILITY_SWAP_HPP // Note: the implementation of this utility contains various workarounds: // - swap_impl is put outside the boost namespace, to avoid infinite // recursion (causing stack overflow) when swapping objects of a primitive // type. // - swap_impl has 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. // - boost::swap has two template arguments, instead of one, to // avoid ambiguity when swapping objects of a Boost type that does // not have its own boost::swap overload. #include <algorithm> //for std::swap #include <cstddef> //for std::size_t namespace boost_swap_impl { template<class T> void swap_impl(T& left, T& right) { using namespace std;//use std::swap if argument dependent lookup fails swap(left,right); } template<class T, std::size_t N> void swap_impl(T (& left)[N], T (& right)[N]) { for (std::size_t i = 0; i < N; ++i) { ::boost_swap_impl::swap_impl(left[i], right[i]); } } } namespace boost { template<class T1, class T2> void swap(T1& left, T2& right) { ::boost_swap_impl::swap_impl(left, right); } } #endif