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