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