include/queue

// -*- C++ -*-
//===--------------------------- queue ------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP_QUEUE
#define _LIBCPP_QUEUE

/*
 queue synopsis

namespace std
{

template <class T, class Container = deque<T>>
class queue
{
public:
 typedef Container container_type;
 typedef typename container_type::value_type value_type;
 typedef typename container_type::reference reference;
 typedef typename container_type::const_reference const_reference;
 typedef typename container_type::size_type size_type;

protected:
 container_type c;

public:
 queue() = default;
 ~queue() = default;

 queue(const queue& q) = default;
 queue(queue&& q) = default;

 queue& operator=(const queue& q) = default;
 queue& operator=(queue&& q) = default;

 explicit queue(const container_type& c);
 explicit queue(container_type&& c)
 template <class Alloc>
 explicit queue(const Alloc& a);
 template <class Alloc>
 queue(const container_type& c, const Alloc& a);
 template <class Alloc>
 queue(container_type&& c, const Alloc& a);
 template <class Alloc>
 queue(const queue& q, const Alloc& a);
 template <class Alloc>
 queue(queue&& q, const Alloc& a);

 bool empty() const;
 size_type size() const;

 reference front();
 const_reference front() const;
 reference back();
 const_reference back() const;

 void push(const value_type& v);
 void push(value_type&& v);
 template <class... Args> void emplace(Args&&... args);
 void pop();

 void swap(queue& q) noexcept(noexcept(swap(c, q.c)));
};

template <class T, class Container>
 bool operator==(const queue<T, Container>& x,const queue<T, Container>& y);

template <class T, class Container>
 bool operator< (const queue<T, Container>& x,const queue<T, Container>& y);

template <class T, class Container>
 bool operator!=(const queue<T, Container>& x,const queue<T, Container>& y);

template <class T, class Container>
 bool operator> (const queue<T, Container>& x,const queue<T, Container>& y);

template <class T, class Container>
 bool operator>=(const queue<T, Container>& x,const queue<T, Container>& y);

template <class T, class Container>
 bool operator<=(const queue<T, Container>& x,const queue<T, Container>& y);

template <class T, class Container>
 void swap(queue<T, Container>& x, queue<T, Container>& y)
 noexcept(noexcept(x.swap(y)));

template <class T, class Container = vector<T>,
 class Compare = less<typename Container::value_type>>
class priority_queue
{
public:
 typedef Container container_type;
 typedef typename container_type::value_type value_type;
 typedef typename container_type::reference reference;
 typedef typename container_type::const_reference const_reference;
 typedef typename container_type::size_type size_type;

protected:
 container_type c;
 Compare comp;

public:
 priority_queue() = default;
 ~priority_queue() = default;

 priority_queue(const priority_queue& q) = default;
 priority_queue(priority_queue&& q) = default;

 priority_queue& operator=(const priority_queue& q) = default;
 priority_queue& operator=(priority_queue&& q) = default;

 explicit priority_queue(const Compare& comp);
 priority_queue(const Compare& comp, const container_type& c);
 explicit priority_queue(const Compare& comp, container_type&& c);
 template <class InputIterator>
 priority_queue(InputIterator first, InputIterator last,
 const Compare& comp = Compare());
 template <class InputIterator>
 priority_queue(InputIterator first, InputIterator last,
 const Compare& comp, const container_type& c);
 template <class InputIterator>
 priority_queue(InputIterator first, InputIterator last,
 const Compare& comp, container_type&& c);
 template <class Alloc>
 explicit priority_queue(const Alloc& a);
 template <class Alloc>
 priority_queue(const Compare& comp, const Alloc& a);
 template <class Alloc>
 priority_queue(const Compare& comp, const container_type& c,
 const Alloc& a);
 template <class Alloc>
 priority_queue(const Compare& comp, container_type&& c,
 const Alloc& a);
 template <class Alloc>
 priority_queue(const priority_queue& q, const Alloc& a);
 template <class Alloc>
 priority_queue(priority_queue&& q, const Alloc& a);

 bool empty() const;
 size_type size() const;
 const_reference top() const;

 void push(const value_type& v);
 void push(value_type&& v);
 template <class... Args> void emplace(Args&&... args);
 void pop();

 void swap(priority_queue& q)
 noexcept(noexcept(swap(c, q.c)) && noexcept(swap(comp.q.comp)));
};

template <class T, class Container, class Compare>
 void swap(priority_queue<T, Container, Compare>& x,
 priority_queue<T, Container, Compare>& y)
 noexcept(noexcept(x.swap(y)));

} // std

*/

#include <__config>
#include <deque>
#include <vector>
#include <functional>
#include <algorithm>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif

_LIBCPP_BEGIN_NAMESPACE_STD

template <class _Tp, class _Container = deque<_Tp> > class _LIBCPP_TYPE_VIS_ONLY queue;

template <class _Tp, class _Container>
_LIBCPP_INLINE_VISIBILITY
bool
operator==(const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y);

template <class _Tp, class _Container>
_LIBCPP_INLINE_VISIBILITY
bool
operator< (const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y);

template <class _Tp, class _Container /*= deque<_Tp>*/>
class _LIBCPP_TYPE_VIS_ONLY queue
{
public:
 typedef _Container container_type;
 typedef typename container_type::value_type value_type;
 typedef typename container_type::reference reference;
 typedef typename container_type::const_reference const_reference;
 typedef typename container_type::size_type size_type;
 static_assert((is_same<_Tp, value_type>::value), "" );

protected:
 container_type c;

public:
 _LIBCPP_INLINE_VISIBILITY
 queue()
 _NOEXCEPT_(is_nothrow_default_constructible<container_type>::value)
 : c() {}

 _LIBCPP_INLINE_VISIBILITY
 queue(const queue& __q) : c(__q.c) {}

#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 _LIBCPP_INLINE_VISIBILITY
 queue(queue&& __q)
 _NOEXCEPT_(is_nothrow_move_constructible<container_type>::value)
 : c(_VSTD::move(__q.c)) {}
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES

 _LIBCPP_INLINE_VISIBILITY
 queue& operator=(const queue& __q) {c = __q.c; return *this;}

#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 _LIBCPP_INLINE_VISIBILITY
 queue& operator=(queue&& __q)
 _NOEXCEPT_(is_nothrow_move_assignable<container_type>::value)
 {c = _VSTD::move(__q.c); return *this;}
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES

 _LIBCPP_INLINE_VISIBILITY
 explicit queue(const container_type& __c) : c(__c) {}
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 _LIBCPP_INLINE_VISIBILITY
 explicit queue(container_type&& __c) : c(_VSTD::move(__c)) {}
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 template <class _Alloc>
 _LIBCPP_INLINE_VISIBILITY
 explicit queue(const _Alloc& __a,
 typename enable_if<uses_allocator<container_type,
 _Alloc>::value>::type* = 0)
 : c(__a) {}
 template <class _Alloc>
 _LIBCPP_INLINE_VISIBILITY
 queue(const queue& __q, const _Alloc& __a,
 typename enable_if<uses_allocator<container_type,
 _Alloc>::value>::type* = 0)
 : c(__q.c, __a) {}
 template <class _Alloc>
 _LIBCPP_INLINE_VISIBILITY
 queue(const container_type& __c, const _Alloc& __a,
 typename enable_if<uses_allocator<container_type,
 _Alloc>::value>::type* = 0)
 : c(__c, __a) {}
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 template <class _Alloc>
 _LIBCPP_INLINE_VISIBILITY
 queue(container_type&& __c, const _Alloc& __a,
 typename enable_if<uses_allocator<container_type,
 _Alloc>::value>::type* = 0)
 : c(_VSTD::move(__c), __a) {}
 template <class _Alloc>
 _LIBCPP_INLINE_VISIBILITY
 queue(queue&& __q, const _Alloc& __a,
 typename enable_if<uses_allocator<container_type,
 _Alloc>::value>::type* = 0)
 : c(_VSTD::move(__q.c), __a) {}

#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES

 _LIBCPP_INLINE_VISIBILITY
 bool empty() const {return c.empty();}
 _LIBCPP_INLINE_VISIBILITY
 size_type size() const {return c.size();}

 _LIBCPP_INLINE_VISIBILITY
 reference front() {return c.front();}
 _LIBCPP_INLINE_VISIBILITY
 const_reference front() const {return c.front();}
 _LIBCPP_INLINE_VISIBILITY
 reference back() {return c.back();}
 _LIBCPP_INLINE_VISIBILITY
 const_reference back() const {return c.back();}

 _LIBCPP_INLINE_VISIBILITY
 void push(const value_type& __v) {c.push_back(__v);}
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 _LIBCPP_INLINE_VISIBILITY
 void push(value_type&& __v) {c.push_back(_VSTD::move(__v));}
#ifndef _LIBCPP_HAS_NO_VARIADICS
 template <class... _Args>
 _LIBCPP_INLINE_VISIBILITY
 void emplace(_Args&&... __args)
 {c.emplace_back(_VSTD::forward<_Args>(__args)...);}
#endif // _LIBCPP_HAS_NO_VARIADICS
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 _LIBCPP_INLINE_VISIBILITY
 void pop() {c.pop_front();}

 _LIBCPP_INLINE_VISIBILITY
 void swap(queue& __q)
 _NOEXCEPT_(__is_nothrow_swappable<container_type>::value)
 {
 using _VSTD::swap;
 swap(c, __q.c);
 }

 template <class _T1, class _C1>
 friend
 _LIBCPP_INLINE_VISIBILITY
 bool
 operator==(const queue<_T1, _C1>& __x,const queue<_T1, _C1>& __y);

 template <class _T1, class _C1>
 friend
 _LIBCPP_INLINE_VISIBILITY
 bool
 operator< (const queue<_T1, _C1>& __x,const queue<_T1, _C1>& __y);
};

template <class _Tp, class _Container>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator==(const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y)
{
 return __x.c == __y.c;
}

template <class _Tp, class _Container>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator< (const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y)
{
 return __x.c < __y.c;
}

template <class _Tp, class _Container>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator!=(const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y)
{
 return !(__x == __y);
}

template <class _Tp, class _Container>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator> (const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y)
{
 return __y < __x;
}

template <class _Tp, class _Container>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator>=(const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y)
{
 return !(__x < __y);
}

template <class _Tp, class _Container>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator<=(const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y)
{
 return !(__y < __x);
}

template <class _Tp, class _Container>
inline _LIBCPP_INLINE_VISIBILITY
void
swap(queue<_Tp, _Container>& __x, queue<_Tp, _Container>& __y)
 _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
{
 __x.swap(__y);
}

template <class _Tp, class _Container, class _Alloc>
struct _LIBCPP_TYPE_VIS_ONLY uses_allocator<queue<_Tp, _Container>, _Alloc>
 : public uses_allocator<_Container, _Alloc>
{
};

template <class _Tp, class _Container = vector<_Tp>,
 class _Compare = less<typename _Container::value_type> >
class _LIBCPP_TYPE_VIS_ONLY priority_queue
{
public:
 typedef _Container container_type;
 typedef _Compare value_compare;
 typedef typename container_type::value_type value_type;
 typedef typename container_type::reference reference;
 typedef typename container_type::const_reference const_reference;
 typedef typename container_type::size_type size_type;
 static_assert((is_same<_Tp, value_type>::value), "" );

protected:
 container_type c;
 value_compare comp;

public:
 _LIBCPP_INLINE_VISIBILITY
 priority_queue()
 _NOEXCEPT_(is_nothrow_default_constructible<container_type>::value &&
 is_nothrow_default_constructible<value_compare>::value)
 : c(), comp() {}

 _LIBCPP_INLINE_VISIBILITY
 priority_queue(const priority_queue& __q) : c(__q.c), comp(__q.comp) {}

#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 _LIBCPP_INLINE_VISIBILITY
 priority_queue(priority_queue&& __q)
 _NOEXCEPT_(is_nothrow_move_constructible<container_type>::value &&
 is_nothrow_move_constructible<value_compare>::value)
 : c(_VSTD::move(__q.c)), comp(_VSTD::move(__q.comp)) {}
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES

 _LIBCPP_INLINE_VISIBILITY
 priority_queue& operator=(const priority_queue& __q)
 {c = __q.c; comp = __q.comp; return *this;}

#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 _LIBCPP_INLINE_VISIBILITY
 priority_queue& operator=(priority_queue&& __q)
 _NOEXCEPT_(is_nothrow_move_assignable<container_type>::value &&
 is_nothrow_move_assignable<value_compare>::value)
 {c = _VSTD::move(__q.c); comp = _VSTD::move(__q.comp); return *this;}
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES

 _LIBCPP_INLINE_VISIBILITY
 explicit priority_queue(const value_compare& __comp)
 : c(), comp(__comp) {}
 priority_queue(const value_compare& __comp, const container_type& __c);
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 explicit priority_queue(const value_compare& __comp, container_type&& __c);
#endif
 template <class _InputIter>
 priority_queue(_InputIter __f, _InputIter __l,
 const value_compare& __comp = value_compare());
 template <class _InputIter>
 priority_queue(_InputIter __f, _InputIter __l,
 const value_compare& __comp, const container_type& __c);
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 template <class _InputIter>
 priority_queue(_InputIter __f, _InputIter __l,
 const value_compare& __comp, container_type&& __c);
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 template <class _Alloc>
 explicit priority_queue(const _Alloc& __a,
 typename enable_if<uses_allocator<container_type,
 _Alloc>::value>::type* = 0);
 template <class _Alloc>
 priority_queue(const value_compare& __comp, const _Alloc& __a,
 typename enable_if<uses_allocator<container_type,
 _Alloc>::value>::type* = 0);
 template <class _Alloc>
 priority_queue(const value_compare& __comp, const container_type& __c,
 const _Alloc& __a,
 typename enable_if<uses_allocator<container_type,
 _Alloc>::value>::type* = 0);
 template <class _Alloc>
 priority_queue(const priority_queue& __q, const _Alloc& __a,
 typename enable_if<uses_allocator<container_type,
 _Alloc>::value>::type* = 0);
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 template <class _Alloc>
 priority_queue(const value_compare& __comp, container_type&& __c,
 const _Alloc& __a,
 typename enable_if<uses_allocator<container_type,
 _Alloc>::value>::type* = 0);
 template <class _Alloc>
 priority_queue(priority_queue&& __q, const _Alloc& __a,
 typename enable_if<uses_allocator<container_type,
 _Alloc>::value>::type* = 0);
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES

 _LIBCPP_INLINE_VISIBILITY
 bool empty() const {return c.empty();}
 _LIBCPP_INLINE_VISIBILITY
 size_type size() const {return c.size();}
 _LIBCPP_INLINE_VISIBILITY
 const_reference top() const {return c.front();}

 void push(const value_type& __v);
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 void push(value_type&& __v);
#ifndef _LIBCPP_HAS_NO_VARIADICS
 template <class... _Args> void emplace(_Args&&... __args);
#endif
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 void pop();

 void swap(priority_queue& __q)
 _NOEXCEPT_(__is_nothrow_swappable<container_type>::value &&
 __is_nothrow_swappable<value_compare>::value);
};

template <class _Tp, class _Container, class _Compare>
inline _LIBCPP_INLINE_VISIBILITY
priority_queue<_Tp, _Container, _Compare>::priority_queue(const _Compare& __comp,
 const container_type& __c)
 : c(__c),
 comp(__comp)
{
 _VSTD::make_heap(c.begin(), c.end(), comp);
}

#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES

template <class _Tp, class _Container, class _Compare>
inline _LIBCPP_INLINE_VISIBILITY
priority_queue<_Tp, _Container, _Compare>::priority_queue(const value_compare& __comp,
 container_type&& __c)
 : c(_VSTD::move(__c)),
 comp(__comp)
{
 _VSTD::make_heap(c.begin(), c.end(), comp);
}

#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES

template <class _Tp, class _Container, class _Compare>
template <class _InputIter>
inline _LIBCPP_INLINE_VISIBILITY
priority_queue<_Tp, _Container, _Compare>::priority_queue(_InputIter __f, _InputIter __l,
 const value_compare& __comp)
 : c(__f, __l),
 comp(__comp)
{
 _VSTD::make_heap(c.begin(), c.end(), comp);
}

template <class _Tp, class _Container, class _Compare>
template <class _InputIter>
inline _LIBCPP_INLINE_VISIBILITY
priority_queue<_Tp, _Container, _Compare>::priority_queue(_InputIter __f, _InputIter __l,
 const value_compare& __comp,
 const container_type& __c)
 : c(__c),
 comp(__comp)
{
 c.insert(c.end(), __f, __l);
 _VSTD::make_heap(c.begin(), c.end(), comp);
}

#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES

template <class _Tp, class _Container, class _Compare>
template <class _InputIter>
inline _LIBCPP_INLINE_VISIBILITY
priority_queue<_Tp, _Container, _Compare>::priority_queue(_InputIter __f, _InputIter __l,
 const value_compare& __comp,
 container_type&& __c)
 : c(_VSTD::move(__c)),
 comp(__comp)
{
 c.insert(c.end(), __f, __l);
 _VSTD::make_heap(c.begin(), c.end(), comp);
}

#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES

template <class _Tp, class _Container, class _Compare>
template <class _Alloc>
inline _LIBCPP_INLINE_VISIBILITY
priority_queue<_Tp, _Container, _Compare>::priority_queue(const _Alloc& __a,
 typename enable_if<uses_allocator<container_type,
 _Alloc>::value>::type*)
 : c(__a)
{
}

template <class _Tp, class _Container, class _Compare>
template <class _Alloc>
inline _LIBCPP_INLINE_VISIBILITY
priority_queue<_Tp, _Container, _Compare>::priority_queue(const value_compare& __comp,
 const _Alloc& __a,
 typename enable_if<uses_allocator<container_type,
 _Alloc>::value>::type*)
 : c(__a),
 comp(__comp)
{
}

template <class _Tp, class _Container, class _Compare>
template <class _Alloc>
inline _LIBCPP_INLINE_VISIBILITY
priority_queue<_Tp, _Container, _Compare>::priority_queue(const value_compare& __comp,
 const container_type& __c,
 const _Alloc& __a,
 typename enable_if<uses_allocator<container_type,
 _Alloc>::value>::type*)
 : c(__c, __a),
 comp(__comp)
{
 _VSTD::make_heap(c.begin(), c.end(), comp);
}

template <class _Tp, class _Container, class _Compare>
template <class _Alloc>
inline _LIBCPP_INLINE_VISIBILITY
priority_queue<_Tp, _Container, _Compare>::priority_queue(const priority_queue& __q,
 const _Alloc& __a,
 typename enable_if<uses_allocator<container_type,
 _Alloc>::value>::type*)
 : c(__q.c, __a),
 comp(__q.comp)
{
 _VSTD::make_heap(c.begin(), c.end(), comp);
}

#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES

template <class _Tp, class _Container, class _Compare>
template <class _Alloc>
inline _LIBCPP_INLINE_VISIBILITY
priority_queue<_Tp, _Container, _Compare>::priority_queue(const value_compare& __comp,
 container_type&& __c,
 const _Alloc& __a,
 typename enable_if<uses_allocator<container_type,
 _Alloc>::value>::type*)
 : c(_VSTD::move(__c), __a),
 comp(__comp)
{
 _VSTD::make_heap(c.begin(), c.end(), comp);
}

template <class _Tp, class _Container, class _Compare>
template <class _Alloc>
inline _LIBCPP_INLINE_VISIBILITY
priority_queue<_Tp, _Container, _Compare>::priority_queue(priority_queue&& __q,
 const _Alloc& __a,
 typename enable_if<uses_allocator<container_type,
 _Alloc>::value>::type*)
 : c(_VSTD::move(__q.c), __a),
 comp(_VSTD::move(__q.comp))
{
 _VSTD::make_heap(c.begin(), c.end(), comp);
}

#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES

template <class _Tp, class _Container, class _Compare>
inline _LIBCPP_INLINE_VISIBILITY
void
priority_queue<_Tp, _Container, _Compare>::push(const value_type& __v)
{
 c.push_back(__v);
 _VSTD::push_heap(c.begin(), c.end(), comp);
}

#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES

template <class _Tp, class _Container, class _Compare>
inline _LIBCPP_INLINE_VISIBILITY
void
priority_queue<_Tp, _Container, _Compare>::push(value_type&& __v)
{
 c.push_back(_VSTD::move(__v));
 _VSTD::push_heap(c.begin(), c.end(), comp);
}

#ifndef _LIBCPP_HAS_NO_VARIADICS

template <class _Tp, class _Container, class _Compare>
template <class... _Args>
inline _LIBCPP_INLINE_VISIBILITY
void
priority_queue<_Tp, _Container, _Compare>::emplace(_Args&&... __args)
{
 c.emplace_back(_VSTD::forward<_Args>(__args)...);
 _VSTD::push_heap(c.begin(), c.end(), comp);
}

#endif // _LIBCPP_HAS_NO_VARIADICS
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES

template <class _Tp, class _Container, class _Compare>
inline _LIBCPP_INLINE_VISIBILITY
void
priority_queue<_Tp, _Container, _Compare>::pop()
{
 _VSTD::pop_heap(c.begin(), c.end(), comp);
 c.pop_back();
}

template <class _Tp, class _Container, class _Compare>
inline _LIBCPP_INLINE_VISIBILITY
void
priority_queue<_Tp, _Container, _Compare>::swap(priority_queue& __q)
 _NOEXCEPT_(__is_nothrow_swappable<container_type>::value &&
 __is_nothrow_swappable<value_compare>::value)
{
 using _VSTD::swap;
 swap(c, __q.c);
 swap(comp, __q.comp);
}

template <class _Tp, class _Container, class _Compare>
inline _LIBCPP_INLINE_VISIBILITY
void
swap(priority_queue<_Tp, _Container, _Compare>& __x,
 priority_queue<_Tp, _Container, _Compare>& __y)
 _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
{
 __x.swap(__y);
}

template <class _Tp, class _Container, class _Compare, class _Alloc>
struct _LIBCPP_TYPE_VIS_ONLY uses_allocator<priority_queue<_Tp, _Container, _Compare>, _Alloc>
 : public uses_allocator<_Container, _Alloc>
{
};

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP_QUEUE