// class template tuple -*- C++ -*-
// Copyright (C) 2004-2013 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/** @file tr1/tuple
* This is a TR1 C++ Library header.
*/
// Chris Jefferson <chris@bubblescope.net>
// Variadic Templates support by Douglas Gregor <doug.gregor@gmail.com>
#ifndef _GLIBCXX_TR1_TUPLE
#define _GLIBCXX_TR1_TUPLE 1
#pragma GCC system_header
#include <utility>
namespace std _GLIBCXX_VISIBILITY(default)
{
namespace tr1
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
// Adds a const reference to a non-reference type.
template<typename _Tp>
struct __add_c_ref
{ typedef const _Tp& type; };
template<typename _Tp>
struct __add_c_ref<_Tp&>
{ typedef _Tp& type; };
// Adds a reference to a non-reference type.
template<typename _Tp>
struct __add_ref
{ typedef _Tp& type; };
template<typename _Tp>
struct __add_ref<_Tp&>
{ typedef _Tp& type; };
/**
* Contains the actual implementation of the @c tuple template, stored
* as a recursive inheritance hierarchy from the first element (most
* derived class) to the last (least derived class). The @c Idx
* parameter gives the 0-based index of the element stored at this
* point in the hierarchy; we use it to implement a constant-time
* get() operation.
*/
template<int _Idx, typename... _Elements>
struct _Tuple_impl;
/**
* Zero-element tuple implementation. This is the basis case for the
* inheritance recursion.
*/
template<int _Idx>
struct _Tuple_impl<_Idx> { };
/**
* Recursive tuple implementation. Here we store the @c Head element
* and derive from a @c Tuple_impl containing the remaining elements
* (which contains the @c Tail).
*/
template<int _Idx, typename _Head, typename... _Tail>
struct _Tuple_impl<_Idx, _Head, _Tail...>
: public _Tuple_impl<_Idx + 1, _Tail...>
{
typedef _Tuple_impl<_Idx + 1, _Tail...> _Inherited;
_Head _M_head;
_Inherited& _M_tail() { return *this; }
const _Inherited& _M_tail() const { return *this; }
_Tuple_impl() : _Inherited(), _M_head() { }
explicit
_Tuple_impl(typename __add_c_ref<_Head>::type __head,
typename __add_c_ref<_Tail>::type... __tail)
: _Inherited(__tail...), _M_head(__head) { }
template<typename... _UElements>
_Tuple_impl(const _Tuple_impl<_Idx, _UElements...>& __in)
: _Inherited(__in._M_tail()), _M_head(__in._M_head) { }
_Tuple_impl(const _Tuple_impl& __in)
: _Inherited(__in._M_tail()), _M_head(__in._M_head) { }
template<typename... _UElements>
_Tuple_impl&
operator=(const _Tuple_impl<_Idx, _UElements...>& __in)
{
_M_head = __in._M_head;
_M_tail() = __in._M_tail();
return *this;
}
_Tuple_impl&
operator=(const _Tuple_impl& __in)
{
_M_head = __in._M_head;
_M_tail() = __in._M_tail();
return *this;
}
};
template<typename... _Elements>
class tuple : public _Tuple_impl<0, _Elements...>
{
typedef _Tuple_impl<0, _Elements...> _Inherited;
public:
tuple() : _Inherited() { }
explicit
tuple(typename __add_c_ref<_Elements>::type... __elements)
: _Inherited(__elements...) { }
template<typename... _UElements>
tuple(const tuple<_UElements...>& __in)
: _Inherited(__in) { }
tuple(const tuple& __in)
: _Inherited(__in) { }
template<typename... _UElements>
tuple&
operator=(const tuple<_UElements...>& __in)
{
static_cast<_Inherited&>(*this) = __in;
return *this;
}
tuple&
operator=(const tuple& __in)
{
static_cast<_Inherited&>(*this) = __in;
return *this;
}
};
template<> class tuple<> { };
// 2-element tuple, with construction and assignment from a pair.
template<typename _T1, typename _T2>
class tuple<_T1, _T2> : public _Tuple_impl<0, _T1, _T2>
{
typedef _Tuple_impl<0, _T1, _T2> _Inherited;
public:
tuple() : _Inherited() { }
explicit
tuple(typename __add_c_ref<_T1>::type __a1,
typename __add_c_ref<_T2>::type __a2)
: _Inherited(__a1, __a2) { }
template<typename _U1, typename _U2>
tuple(const tuple<_U1, _U2>& __in)
: _Inherited(__in) { }
tuple(const tuple& __in)
: _Inherited(__in) { }
template<typename _U1, typename _U2>
tuple(const pair<_U1, _U2>& __in)
: _Inherited(_Tuple_impl<0,
typename __add_c_ref<_U1>::type,
typename __add_c_ref<_U2>::type>(__in.first,
__in.second))
{ }
template<typename _U1, typename _U2>
tuple&
operator=(const tuple<_U1, _U2>& __in)
{
static_cast<_Inherited&>(*this) = __in;
return *this;
}
tuple&
operator=(const tuple& __in)
{
static_cast<_Inherited&>(*this) = __in;
return *this;
}
template<typename _U1, typename _U2>
tuple&
operator=(const pair<_U1, _U2>& __in)
{
this->_M_head = __in.first;
this->_M_tail()._M_head = __in.second;
return *this;
}
};
/// Gives the type of the ith element of a given tuple type.
template<int __i, typename _Tp>
struct tuple_element;
/**
* Recursive case for tuple_element: strip off the first element in
* the tuple and retrieve the (i-1)th element of the remaining tuple.
*/
template<int __i, typename _Head, typename... _Tail>
struct tuple_element<__i, tuple<_Head, _Tail...> >
: tuple_element<__i - 1, tuple<_Tail...> > { };
/**
* Basis case for tuple_element: The first element is the one we're seeking.
*/
template<typename _Head, typename... _Tail>
struct tuple_element<0, tuple<_Head, _Tail...> >
{
typedef _Head type;
};
/// Finds the size of a given tuple type.
template<typename _Tp>
struct tuple_size;
/// class tuple_size
template<typename... _Elements>
struct tuple_size<tuple<_Elements...> >
{
static const int value = sizeof...(_Elements);
};
template<typename... _Elements>
const int tuple_size<tuple<_Elements...> >::value;
template<int __i, typename _Head, typename... _Tail>
inline typename __add_ref<_Head>::type
__get_helper(_Tuple_impl<__i, _Head, _Tail...>& __t)
{
return __t._M_head;
}
template<int __i, typename _Head, typename... _Tail>
inline typename __add_c_ref<_Head>::type
__get_helper(const _Tuple_impl<__i, _Head, _Tail...>& __t)
{
return __t._M_head;
}
// Return a reference (const reference) to the ith element of a tuple.
// Any const or non-const ref elements are returned with their original type.
template<int __i, typename... _Elements>
inline typename __add_ref<
typename tuple_element<__i, tuple<_Elements...> >::type
>::type
get(tuple<_Elements...>& __t)
{
return __get_helper<__i>(__t);
}
template<int __i, typename... _Elements>
inline typename __add_c_ref<
typename tuple_element<__i, tuple<_Elements...> >::type
>::type
get(const tuple<_Elements...>& __t)
{
return __get_helper<__i>(__t);
}
// This class helps construct the various comparison operations on tuples
template<int __check_equal_size, int __i, int __j,
typename _Tp, typename _Up>
struct __tuple_compare;
template<int __i, int __j, typename _Tp, typename _Up>
struct __tuple_compare<0, __i, __j, _Tp, _Up>
{
static bool __eq(const _Tp& __t, const _Up& __u)
{
return (get<__i>(__t) == get<__i>(__u) &&
__tuple_compare<0, __i+1, __j, _Tp, _Up>::__eq(__t, __u));
}
static bool __less(const _Tp& __t, const _Up& __u)
{
return ((get<__i>(__t) < get<__i>(__u))
|| !(get<__i>(__u) < get<__i>(__t)) &&
__tuple_compare<0, __i+1, __j, _Tp, _Up>::__less(__t, __u));
}
};
template<int __i, typename _Tp, typename _Up>
struct __tuple_compare<0, __i, __i, _Tp, _Up>
{
static bool __eq(const _Tp&, const _Up&)
{ return true; }
static bool __less(const _Tp&, const _Up&)
{ return false; }
};
template<typename... _TElements, typename... _UElements>
bool
operator==(const tuple<_TElements...>& __t,
const tuple<_UElements...>& __u)
{
typedef tuple<_TElements...> _Tp;
typedef tuple<_UElements...> _Up;
return (__tuple_compare<tuple_size<_Tp>::value - tuple_size<_Up>::value,
0, tuple_size<_Tp>::value, _Tp, _Up>::__eq(__t, __u));
}
template<typename... _TElements, typename... _UElements>
bool
operator<(const tuple<_TElements...>& __t,
const tuple<_UElements...>& __u)
{
typedef tuple<_TElements...> _Tp;
typedef tuple<_UElements...> _Up;
return (__tuple_compare<tuple_size<_Tp>::value - tuple_size<_Up>::value,
0, tuple_size<_Tp>::value, _Tp, _Up>::__less(__t, __u));
}
template<typename... _TElements, typename... _UElements>
inline bool
operator!=(const tuple<_TElements...>& __t,
const tuple<_UElements...>& __u)
{ return !(__t == __u); }
template<typename... _TElements, typename... _UElements>
inline bool
operator>(const tuple<_TElements...>& __t,
const tuple<_UElements...>& __u)
{ return __u < __t; }
template<typename... _TElements, typename... _UElements>
inline bool
operator<=(const tuple<_TElements...>& __t,
const tuple<_UElements...>& __u)
{ return !(__u < __t); }
template<typename... _TElements, typename... _UElements>
inline bool
operator>=(const tuple<_TElements...>& __t,
const tuple<_UElements...>& __u)
{ return !(__t < __u); }
template<typename _Tp>
class reference_wrapper;
// Helper which adds a reference to a type when given a reference_wrapper
template<typename _Tp>
struct __strip_reference_wrapper
{
typedef _Tp __type;
};
template<typename _Tp>
struct __strip_reference_wrapper<reference_wrapper<_Tp> >
{
typedef _Tp& __type;
};
template<typename _Tp>
struct __strip_reference_wrapper<const reference_wrapper<_Tp> >
{
typedef _Tp& __type;
};
template<typename... _Elements>
inline tuple<typename __strip_reference_wrapper<_Elements>::__type...>
make_tuple(_Elements... __args)
{
typedef tuple<typename __strip_reference_wrapper<_Elements>::__type...>
__result_type;
return __result_type(__args...);
}
template<typename... _Elements>
inline tuple<_Elements&...>
tie(_Elements&... __args)
{
return tuple<_Elements&...>(__args...);
}
// A class (and instance) which can be used in 'tie' when an element
// of a tuple is not required
struct _Swallow_assign
{
template<class _Tp>
_Swallow_assign&
operator=(const _Tp&)
{ return *this; }
};
// TODO: Put this in some kind of shared file.
namespace
{
_Swallow_assign ignore;
}; // anonymous namespace
_GLIBCXX_END_NAMESPACE_VERSION
}
}
#endif // _GLIBCXX_TR1_TUPLE