utility/include/boost/detail/compressed_pair.hpp
Beman Dawes 06adfe9658 This commit was generated by cvs2svn to compensate for changes in r4,
which included commits to RCS files with non-trunk default branches.


[SVN r7621]
2000-07-07 16:04:40 +00:00

421 lines
15 KiB
C++

// (C) Copyright Steve Cleary, Beman Dawes, Howard Hinnant & John Maddock 2000.
// Permission to copy, use, modify, sell and
// distribute this software is granted provided this copyright notice appears
// in all copies. This software is provided "as is" without express or implied
// warranty, and with no claim as to its suitability for any purpose.
// See http://www.boost.org for most recent version including documentation.
//
// 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>
#ifndef BOOST_TYPE_TRAITS_HPP
#include <boost/type_traits.hpp>
#endif
#ifndef BOOST_CALL_TRAITS_HPP
#include <boost/call_traits.hpp>
#endif
namespace boost
{
// 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)
{
using std::swap;
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) {}
explicit compressed_pair_imp(first_param_type x)
: first_(x) {}
explicit 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(compressed_pair_imp& 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>
: private T1
{
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) {}
explicit compressed_pair_imp(first_param_type x)
: first_type(x) {}
explicit 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(compressed_pair_imp& 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>
: private T2
{
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) {}
explicit compressed_pair_imp(first_param_type x)
: first_(x) {}
explicit 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(compressed_pair_imp& 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>
: private T1,
private T2
{
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) {}
explicit compressed_pair_imp(first_param_type x)
: first_type(x) {}
explicit 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(compressed_pair_imp&) {}
};
// JM
// 4 T1 == T2, T1 and T2 both empty
// Note does not actually store an instance of T2 at all -
// but reuses T1 base class for both first() and second().
template <class T1, class T2>
class compressed_pair_imp<T1, T2, 4>
: private T1
{
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)
: first_type(x) {}
explicit compressed_pair_imp(first_param_type x)
: first_type(x) {}
first_reference first() {return *this;}
first_const_reference first() const {return *this;}
second_reference second() {return *this;}
second_const_reference second() const {return *this;}
void swap(compressed_pair_imp&) {}
private:
};
// 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) {}
explicit 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(compressed_pair_imp<T1, T2, 5>& 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) {}
explicit 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(compressed_pair& 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
#endif // BOOST_DETAIL_COMPRESSED_PAIR_HPP