sl@0: //  (C) Copyright Steve Cleary, Beman Dawes, Howard Hinnant & John Maddock 2000.
sl@0: //  Use, modification and distribution are subject to the Boost Software License,
sl@0: //  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
sl@0: //  http://www.boost.org/LICENSE_1_0.txt).
sl@0: //
sl@0: //  See http://www.boost.org/libs/utility for most recent version including documentation.
sl@0: 
sl@0: // compressed_pair: pair that "compresses" empty members
sl@0: // (see libs/utility/compressed_pair.htm)
sl@0: //
sl@0: // JM changes 25 Jan 2004:
sl@0: // For the case where T1 == T2 and both are empty, then first() and second()
sl@0: // should return different objects.
sl@0: // JM changes 25 Jan 2000:
sl@0: // Removed default arguments from compressed_pair_switch to get
sl@0: // C++ Builder 4 to accept them
sl@0: // rewriten swap to get gcc and C++ builder to compile.
sl@0: // added partial specialisations for case T1 == T2 to avoid duplicate constructor defs.
sl@0: 
sl@0: #ifndef BOOST_DETAIL_COMPRESSED_PAIR_HPP
sl@0: #define BOOST_DETAIL_COMPRESSED_PAIR_HPP
sl@0: 
sl@0: #include <algorithm>
sl@0: 
sl@0: #include <boost/type_traits/remove_cv.hpp>
sl@0: #include <boost/type_traits/is_empty.hpp>
sl@0: #include <boost/type_traits/is_same.hpp>
sl@0: #include <boost/call_traits.hpp>
sl@0: 
sl@0: #ifdef BOOST_MSVC
sl@0: # pragma warning(push)
sl@0: # pragma warning(disable:4512)
sl@0: #endif 
sl@0: namespace boost
sl@0: {
sl@0: 
sl@0: template <class T1, class T2>
sl@0: class compressed_pair;
sl@0: 
sl@0: 
sl@0: // compressed_pair
sl@0: 
sl@0: namespace details
sl@0: {
sl@0:    // JM altered 26 Jan 2000:
sl@0:    template <class T1, class T2, bool IsSame, bool FirstEmpty, bool SecondEmpty>
sl@0:    struct compressed_pair_switch;
sl@0: 
sl@0:    template <class T1, class T2>
sl@0:    struct compressed_pair_switch<T1, T2, false, false, false>
sl@0:       {static const int value = 0;};
sl@0: 
sl@0:    template <class T1, class T2>
sl@0:    struct compressed_pair_switch<T1, T2, false, true, true>
sl@0:       {static const int value = 3;};
sl@0: 
sl@0:    template <class T1, class T2>
sl@0:    struct compressed_pair_switch<T1, T2, false, true, false>
sl@0:       {static const int value = 1;};
sl@0: 
sl@0:    template <class T1, class T2>
sl@0:    struct compressed_pair_switch<T1, T2, false, false, true>
sl@0:       {static const int value = 2;};
sl@0: 
sl@0:    template <class T1, class T2>
sl@0:    struct compressed_pair_switch<T1, T2, true, true, true>
sl@0:       {static const int value = 4;};
sl@0: 
sl@0:    template <class T1, class T2>
sl@0:    struct compressed_pair_switch<T1, T2, true, false, false>
sl@0:       {static const int value = 5;};
sl@0: 
sl@0:    template <class T1, class T2, int Version> class compressed_pair_imp;
sl@0: 
sl@0: #ifdef __GNUC__
sl@0:    // workaround for GCC (JM):
sl@0:    using std::swap;
sl@0: #endif
sl@0:    //
sl@0:    // can't call unqualified swap from within classname::swap
sl@0:    // as Koenig lookup rules will find only the classname::swap
sl@0:    // member function not the global declaration, so use cp_swap
sl@0:    // as a forwarding function (JM):
sl@0:    template <typename T>
sl@0:    inline void cp_swap(T& t1, T& t2)
sl@0:    {
sl@0: #ifndef __GNUC__
sl@0:       using std::swap;
sl@0: #endif
sl@0:       swap(t1, t2);
sl@0:    }
sl@0: 
sl@0:    // 0    derive from neither
sl@0: 
sl@0:    template <class T1, class T2>
sl@0:    class compressed_pair_imp<T1, T2, 0>
sl@0:    {
sl@0:    public:
sl@0:       typedef T1                                                 first_type;
sl@0:       typedef T2                                                 second_type;
sl@0:       typedef typename call_traits<first_type>::param_type       first_param_type;
sl@0:       typedef typename call_traits<second_type>::param_type      second_param_type;
sl@0:       typedef typename call_traits<first_type>::reference        first_reference;
sl@0:       typedef typename call_traits<second_type>::reference       second_reference;
sl@0:       typedef typename call_traits<first_type>::const_reference  first_const_reference;
sl@0:       typedef typename call_traits<second_type>::const_reference second_const_reference;
sl@0: 
sl@0:       compressed_pair_imp() {} 
sl@0: 
sl@0:       compressed_pair_imp(first_param_type x, second_param_type y)
sl@0:          : first_(x), second_(y) {}
sl@0: 
sl@0:       compressed_pair_imp(first_param_type x)
sl@0:          : first_(x) {}
sl@0: 
sl@0:       compressed_pair_imp(second_param_type y)
sl@0:          : second_(y) {}
sl@0: 
sl@0:       first_reference       first()       {return first_;}
sl@0:       first_const_reference first() const {return first_;}
sl@0: 
sl@0:       second_reference       second()       {return second_;}
sl@0:       second_const_reference second() const {return second_;}
sl@0: 
sl@0:       void swap(::boost::compressed_pair<T1, T2>& y)
sl@0:       {
sl@0:          cp_swap(first_, y.first());
sl@0:          cp_swap(second_, y.second());
sl@0:       }
sl@0:    private:
sl@0:       first_type first_;
sl@0:       second_type second_;
sl@0:    };
sl@0: 
sl@0:    // 1    derive from T1
sl@0: 
sl@0:    template <class T1, class T2>
sl@0:    class compressed_pair_imp<T1, T2, 1>
sl@0:       : protected ::boost::remove_cv<T1>::type
sl@0:    {
sl@0:    public:
sl@0:       typedef T1                                                 first_type;
sl@0:       typedef T2                                                 second_type;
sl@0:       typedef typename call_traits<first_type>::param_type       first_param_type;
sl@0:       typedef typename call_traits<second_type>::param_type      second_param_type;
sl@0:       typedef typename call_traits<first_type>::reference        first_reference;
sl@0:       typedef typename call_traits<second_type>::reference       second_reference;
sl@0:       typedef typename call_traits<first_type>::const_reference  first_const_reference;
sl@0:       typedef typename call_traits<second_type>::const_reference second_const_reference;
sl@0: 
sl@0:       compressed_pair_imp() {}
sl@0: 
sl@0:       compressed_pair_imp(first_param_type x, second_param_type y)
sl@0:          : first_type(x), second_(y) {}
sl@0: 
sl@0:       compressed_pair_imp(first_param_type x)
sl@0:          : first_type(x) {}
sl@0: 
sl@0:       compressed_pair_imp(second_param_type y)
sl@0:          : second_(y) {}
sl@0: 
sl@0:       first_reference       first()       {return *this;}
sl@0:       first_const_reference first() const {return *this;}
sl@0: 
sl@0:       second_reference       second()       {return second_;}
sl@0:       second_const_reference second() const {return second_;}
sl@0: 
sl@0:       void swap(::boost::compressed_pair<T1,T2>& y)
sl@0:       {
sl@0:          // no need to swap empty base class:
sl@0:          cp_swap(second_, y.second());
sl@0:       }
sl@0:    private:
sl@0:       second_type second_;
sl@0:    };
sl@0: 
sl@0:    // 2    derive from T2
sl@0: 
sl@0:    template <class T1, class T2>
sl@0:    class compressed_pair_imp<T1, T2, 2>
sl@0:       : protected ::boost::remove_cv<T2>::type
sl@0:    {
sl@0:    public:
sl@0:       typedef T1                                                 first_type;
sl@0:       typedef T2                                                 second_type;
sl@0:       typedef typename call_traits<first_type>::param_type       first_param_type;
sl@0:       typedef typename call_traits<second_type>::param_type      second_param_type;
sl@0:       typedef typename call_traits<first_type>::reference        first_reference;
sl@0:       typedef typename call_traits<second_type>::reference       second_reference;
sl@0:       typedef typename call_traits<first_type>::const_reference  first_const_reference;
sl@0:       typedef typename call_traits<second_type>::const_reference second_const_reference;
sl@0: 
sl@0:       compressed_pair_imp() {}
sl@0: 
sl@0:       compressed_pair_imp(first_param_type x, second_param_type y)
sl@0:          : second_type(y), first_(x) {}
sl@0: 
sl@0:       compressed_pair_imp(first_param_type x)
sl@0:          : first_(x) {}
sl@0: 
sl@0:       compressed_pair_imp(second_param_type y)
sl@0:          : second_type(y) {}
sl@0: 
sl@0:       first_reference       first()       {return first_;}
sl@0:       first_const_reference first() const {return first_;}
sl@0: 
sl@0:       second_reference       second()       {return *this;}
sl@0:       second_const_reference second() const {return *this;}
sl@0: 
sl@0:       void swap(::boost::compressed_pair<T1,T2>& y)
sl@0:       {
sl@0:          // no need to swap empty base class:
sl@0:          cp_swap(first_, y.first());
sl@0:       }
sl@0: 
sl@0:    private:
sl@0:       first_type first_;
sl@0:    };
sl@0: 
sl@0:    // 3    derive from T1 and T2
sl@0: 
sl@0:    template <class T1, class T2>
sl@0:    class compressed_pair_imp<T1, T2, 3>
sl@0:       : protected ::boost::remove_cv<T1>::type,
sl@0:         protected ::boost::remove_cv<T2>::type
sl@0:    {
sl@0:    public:
sl@0:       typedef T1                                                 first_type;
sl@0:       typedef T2                                                 second_type;
sl@0:       typedef typename call_traits<first_type>::param_type       first_param_type;
sl@0:       typedef typename call_traits<second_type>::param_type      second_param_type;
sl@0:       typedef typename call_traits<first_type>::reference        first_reference;
sl@0:       typedef typename call_traits<second_type>::reference       second_reference;
sl@0:       typedef typename call_traits<first_type>::const_reference  first_const_reference;
sl@0:       typedef typename call_traits<second_type>::const_reference second_const_reference;
sl@0: 
sl@0:       compressed_pair_imp() {}
sl@0: 
sl@0:       compressed_pair_imp(first_param_type x, second_param_type y)
sl@0:          : first_type(x), second_type(y) {}
sl@0: 
sl@0:       compressed_pair_imp(first_param_type x)
sl@0:          : first_type(x) {}
sl@0: 
sl@0:       compressed_pair_imp(second_param_type y)
sl@0:          : second_type(y) {}
sl@0: 
sl@0:       first_reference       first()       {return *this;}
sl@0:       first_const_reference first() const {return *this;}
sl@0: 
sl@0:       second_reference       second()       {return *this;}
sl@0:       second_const_reference second() const {return *this;}
sl@0:       //
sl@0:       // no need to swap empty bases:
sl@0:       void swap(::boost::compressed_pair<T1,T2>&) {}
sl@0:    };
sl@0: 
sl@0:    // JM
sl@0:    // 4    T1 == T2, T1 and T2 both empty
sl@0:    //      Originally this did not store an instance of T2 at all
sl@0:    //      but that led to problems beause it meant &x.first() == &x.second()
sl@0:    //      which is not true for any other kind of pair, so now we store an instance
sl@0:    //      of T2 just in case the user is relying on first() and second() returning
sl@0:    //      different objects (albeit both empty).
sl@0:    template <class T1, class T2>
sl@0:    class compressed_pair_imp<T1, T2, 4>
sl@0:       : protected ::boost::remove_cv<T1>::type
sl@0:    {
sl@0:    public:
sl@0:       typedef T1                                                 first_type;
sl@0:       typedef T2                                                 second_type;
sl@0:       typedef typename call_traits<first_type>::param_type       first_param_type;
sl@0:       typedef typename call_traits<second_type>::param_type      second_param_type;
sl@0:       typedef typename call_traits<first_type>::reference        first_reference;
sl@0:       typedef typename call_traits<second_type>::reference       second_reference;
sl@0:       typedef typename call_traits<first_type>::const_reference  first_const_reference;
sl@0:       typedef typename call_traits<second_type>::const_reference second_const_reference;
sl@0: 
sl@0:       compressed_pair_imp() {}
sl@0: 
sl@0:       compressed_pair_imp(first_param_type x, second_param_type y)
sl@0:          : first_type(x), m_second(y) {}
sl@0: 
sl@0:       compressed_pair_imp(first_param_type x)
sl@0:          : first_type(x), m_second(x) {}
sl@0: 
sl@0:       first_reference       first()       {return *this;}
sl@0:       first_const_reference first() const {return *this;}
sl@0: 
sl@0:       second_reference       second()       {return m_second;}
sl@0:       second_const_reference second() const {return m_second;}
sl@0: 
sl@0:       void swap(::boost::compressed_pair<T1,T2>&) {}
sl@0:    private:
sl@0:       T2 m_second;
sl@0:    };
sl@0: 
sl@0:    // 5    T1 == T2 and are not empty:   //JM
sl@0: 
sl@0:    template <class T1, class T2>
sl@0:    class compressed_pair_imp<T1, T2, 5>
sl@0:    {
sl@0:    public:
sl@0:       typedef T1                                                 first_type;
sl@0:       typedef T2                                                 second_type;
sl@0:       typedef typename call_traits<first_type>::param_type       first_param_type;
sl@0:       typedef typename call_traits<second_type>::param_type      second_param_type;
sl@0:       typedef typename call_traits<first_type>::reference        first_reference;
sl@0:       typedef typename call_traits<second_type>::reference       second_reference;
sl@0:       typedef typename call_traits<first_type>::const_reference  first_const_reference;
sl@0:       typedef typename call_traits<second_type>::const_reference second_const_reference;
sl@0: 
sl@0:       compressed_pair_imp() {}
sl@0: 
sl@0:       compressed_pair_imp(first_param_type x, second_param_type y)
sl@0:          : first_(x), second_(y) {}
sl@0: 
sl@0:       compressed_pair_imp(first_param_type x)
sl@0:          : first_(x), second_(x) {}
sl@0: 
sl@0:       first_reference       first()       {return first_;}
sl@0:       first_const_reference first() const {return first_;}
sl@0: 
sl@0:       second_reference       second()       {return second_;}
sl@0:       second_const_reference second() const {return second_;}
sl@0: 
sl@0:       void swap(::boost::compressed_pair<T1, T2>& y)
sl@0:       {
sl@0:          cp_swap(first_, y.first());
sl@0:          cp_swap(second_, y.second());
sl@0:       }
sl@0:    private:
sl@0:       first_type first_;
sl@0:       second_type second_;
sl@0:    };
sl@0: 
sl@0: }  // details
sl@0: 
sl@0: template <class T1, class T2>
sl@0: class compressed_pair
sl@0:    : private ::boost::details::compressed_pair_imp<T1, T2,
sl@0:              ::boost::details::compressed_pair_switch<
sl@0:                     T1,
sl@0:                     T2,
sl@0:                     ::boost::is_same<typename remove_cv<T1>::type, typename remove_cv<T2>::type>::value,
sl@0:                     ::boost::is_empty<T1>::value,
sl@0:                     ::boost::is_empty<T2>::value>::value>
sl@0: {
sl@0: private:
sl@0:    typedef details::compressed_pair_imp<T1, T2,
sl@0:              ::boost::details::compressed_pair_switch<
sl@0:                     T1,
sl@0:                     T2,
sl@0:                     ::boost::is_same<typename remove_cv<T1>::type, typename remove_cv<T2>::type>::value,
sl@0:                     ::boost::is_empty<T1>::value,
sl@0:                     ::boost::is_empty<T2>::value>::value> base;
sl@0: public:
sl@0:    typedef T1                                                 first_type;
sl@0:    typedef T2                                                 second_type;
sl@0:    typedef typename call_traits<first_type>::param_type       first_param_type;
sl@0:    typedef typename call_traits<second_type>::param_type      second_param_type;
sl@0:    typedef typename call_traits<first_type>::reference        first_reference;
sl@0:    typedef typename call_traits<second_type>::reference       second_reference;
sl@0:    typedef typename call_traits<first_type>::const_reference  first_const_reference;
sl@0:    typedef typename call_traits<second_type>::const_reference second_const_reference;
sl@0: 
sl@0:             compressed_pair() : base() {}
sl@0:             compressed_pair(first_param_type x, second_param_type y) : base(x, y) {}
sl@0:    explicit compressed_pair(first_param_type x) : base(x) {}
sl@0:    explicit compressed_pair(second_param_type y) : base(y) {}
sl@0: 
sl@0:    first_reference       first()       {return base::first();}
sl@0:    first_const_reference first() const {return base::first();}
sl@0: 
sl@0:    second_reference       second()       {return base::second();}
sl@0:    second_const_reference second() const {return base::second();}
sl@0: 
sl@0:    void swap(compressed_pair& y) { base::swap(y); }
sl@0: };
sl@0: 
sl@0: // JM
sl@0: // Partial specialisation for case where T1 == T2:
sl@0: //
sl@0: template <class T>
sl@0: class compressed_pair<T, T>
sl@0:    : private details::compressed_pair_imp<T, T,
sl@0:              ::boost::details::compressed_pair_switch<
sl@0:                     T,
sl@0:                     T,
sl@0:                     ::boost::is_same<typename remove_cv<T>::type, typename remove_cv<T>::type>::value,
sl@0:                     ::boost::is_empty<T>::value,
sl@0:                     ::boost::is_empty<T>::value>::value>
sl@0: {
sl@0: private:
sl@0:    typedef details::compressed_pair_imp<T, T,
sl@0:              ::boost::details::compressed_pair_switch<
sl@0:                     T,
sl@0:                     T,
sl@0:                     ::boost::is_same<typename remove_cv<T>::type, typename remove_cv<T>::type>::value,
sl@0:                     ::boost::is_empty<T>::value,
sl@0:                     ::boost::is_empty<T>::value>::value> base;
sl@0: public:
sl@0:    typedef T                                                  first_type;
sl@0:    typedef T                                                  second_type;
sl@0:    typedef typename call_traits<first_type>::param_type       first_param_type;
sl@0:    typedef typename call_traits<second_type>::param_type      second_param_type;
sl@0:    typedef typename call_traits<first_type>::reference        first_reference;
sl@0:    typedef typename call_traits<second_type>::reference       second_reference;
sl@0:    typedef typename call_traits<first_type>::const_reference  first_const_reference;
sl@0:    typedef typename call_traits<second_type>::const_reference second_const_reference;
sl@0: 
sl@0:             compressed_pair() : base() {}
sl@0:             compressed_pair(first_param_type x, second_param_type y) : base(x, y) {}
sl@0: #if !(defined(__SUNPRO_CC) && (__SUNPRO_CC <= 0x530))
sl@0:    explicit 
sl@0: #endif
sl@0:       compressed_pair(first_param_type x) : base(x) {}
sl@0: 
sl@0:    first_reference       first()       {return base::first();}
sl@0:    first_const_reference first() const {return base::first();}
sl@0: 
sl@0:    second_reference       second()       {return base::second();}
sl@0:    second_const_reference second() const {return base::second();}
sl@0: 
sl@0:    void swap(::boost::compressed_pair<T,T>& y) { base::swap(y); }
sl@0: };
sl@0: 
sl@0: template <class T1, class T2>
sl@0: inline
sl@0: void
sl@0: swap(compressed_pair<T1, T2>& x, compressed_pair<T1, T2>& y)
sl@0: {
sl@0:    x.swap(y);
sl@0: }
sl@0: 
sl@0: } // boost
sl@0: 
sl@0: #ifdef BOOST_MSVC
sl@0: # pragma warning(pop)
sl@0: #endif 
sl@0: 
sl@0: #endif // BOOST_DETAIL_COMPRESSED_PAIR_HPP
sl@0: