std::priority_queue< _Tp, _Sequence, _Compare > Class Template Reference

Public Types
typedef _Sequence::const_reference	const_reference
typedef _Sequence	container_type
typedef _Sequence::reference	reference
typedef _Sequence::size_type	size_type
typedef _Compare	value_compare
typedef _Sequence::value_type	value_type

Public Member Functions
template<typename _Seq = _Sequence, typename _Requires = typename enable_if<__and_<is_default_constructible<_Compare>, is_default_constructible<_Seq>>::value>::type>
	priority_queue ()
	priority_queue (const _Compare &__x, const _Sequence &__s)
	priority_queue (const _Compare &__x, _Sequence &&__s=_Sequence())
template<typename _Alloc , typename _Requires = _Uses<_Alloc>>
	priority_queue (const _Alloc &__a)
template<typename _Alloc , typename _Requires = _Uses<_Alloc>>
	priority_queue (const _Compare &__x, const _Alloc &__a)
template<typename _Alloc , typename _Requires = _Uses<_Alloc>>
	priority_queue (const _Compare &__x, const _Sequence &__c, const _Alloc &__a)
template<typename _Alloc , typename _Requires = _Uses<_Alloc>>
	priority_queue (const _Compare &__x, _Sequence &&__c, const _Alloc &__a)
template<typename _Alloc , typename _Requires = _Uses<_Alloc>>
	priority_queue (const priority_queue &__q, const _Alloc &__a)
template<typename _Alloc , typename _Requires = _Uses<_Alloc>>
	priority_queue (priority_queue &&__q, const _Alloc &__a)
template<typename _InputIterator >
	priority_queue (_InputIterator __first, _InputIterator __last, const _Compare &__x, const _Sequence &__s)
template<typename _InputIterator >
	priority_queue (_InputIterator __first, _InputIterator __last, const _Compare &__x=_Compare(), _Sequence &&__s=_Sequence())
template<typename... _Args>
void	emplace (_Args &&... __args)
bool	empty () const
void	pop ()
void	push (const value_type &__x)
void	push (value_type &&__x)
size_type	size () const
void	swap (priority_queue &__pq) noexcept(__and_<//c++1z or gnu++11 __is_nothrow_swappable< _Sequence >, __is_nothrow_swappable< _Compare > >::value)
const_reference	top () const

Protected Attributes
_Sequence	c
_Compare	comp

Detailed Description

template<typename _Tp, typename _Sequence = vector<_Tp>, typename _Compare = less<typename _Sequence::value_type>>
class std::priority_queue< _Tp, _Sequence, _Compare >

A standard container automatically sorting its contents.

Template Parameters

_Tp	Type of element.
_Sequence	Type of underlying sequence, defaults to vector<_Tp>.
_Compare	Comparison function object type, defaults to less<_Sequence::value_type>.

This is not a true container, but an adaptor. It holds another container, and provides a wrapper interface to that container. The wrapper is what enforces priority-based sorting and queue behavior. Very few of the standard container/sequence interface requirements are met (e.g., iterators).

The second template parameter defines the type of the underlying sequence/container. It defaults to std::vector, but it can be any type that supports front(), push_back, pop_back, and random-access iterators, such as std::deque or an appropriate user-defined type.

The third template parameter supplies the means of making priority comparisons. It defaults to less<value_type> but can be anything defining a strict weak ordering.

Members not found in normal containers are container_type, which is a typedef for the second Sequence parameter, and push, pop, and top, which are standard queue operations.

Note

No equality/comparison operators are provided for priority_queue.

Sorting of the elements takes place as they are added to, and removed from, the priority_queue using the priority_queue's member functions. If you access the elements by other means, and change their data such that the sorting order would be different, the priority_queue will not re-sort the elements for you. (How could it know to do so?)

Definition at line 435 of file stl_queue.h.

Constructor & Destructor Documentation

priority_queue() [1/2]

template<typename _Tp, typename _Sequence = vector<_Tp>, typename _Compare = less<typename _Sequence::value_type>>

template<typename _Seq = _Sequence, typename _Requires = typename enable_if<__and_<is_default_constructible<_Compare>, is_default_constructible<_Seq>>::value>::type>

std::priority_queue< _Tp, _Sequence, _Compare >::priority_queue ( )

inline

Default constructor creates no elements.

Definition at line 485 of file stl_queue.h.

priority_queue() [2/2]

template<typename _Tp, typename _Sequence = vector<_Tp>, typename _Compare = less<typename _Sequence::value_type>>

template<typename _InputIterator >

std::priority_queue< _Tp, _Sequence, _Compare >::priority_queue ( _InputIterator  __first, _InputIterator  __last, const _Compare &  __x, const _Sequence &  __s  )

inline

Builds a queue from a range.

Parameters

__first	An input iterator.
__last	An input iterator.
__x	A comparison functor describing a strict weak ordering.
__s	An initial sequence with which to start.

Begins by copying __s, inserting a copy of the elements from [first,last) into the copy of __s, then ordering the copy according to __x.

For more information on function objects, see the documentation on functor base classes.

Definition at line 557 of file stl_queue.h.

Member Function Documentation

empty()

template<typename _Tp, typename _Sequence = vector<_Tp>, typename _Compare = less<typename _Sequence::value_type>>

bool std::priority_queue< _Tp, _Sequence, _Compare >::empty ( ) const

inline

Returns true if the queue is empty.

Definition at line 583 of file stl_queue.h.

pop()

template<typename _Tp, typename _Sequence = vector<_Tp>, typename _Compare = less<typename _Sequence::value_type>>

void std::priority_queue< _Tp, _Sequence, _Compare >::pop ( )

inline

Removes first element.

This is a typical queue operation. It shrinks the queue by one. The time complexity of the operation depends on the underlying sequence.

Note that no data is returned, and if the first element's data is needed, it should be retrieved before pop() is called.

Definition at line 646 of file stl_queue.h.

push()

template<typename _Tp, typename _Sequence = vector<_Tp>, typename _Compare = less<typename _Sequence::value_type>>

void std::priority_queue< _Tp, _Sequence, _Compare >::push ( const value_type &  __x )

inline

Add data to the queue.

Parameters

__x	Data to be added.

This is a typical queue operation. The time complexity of the operation depends on the underlying sequence.

Definition at line 611 of file stl_queue.h.

References std::push_heap().

size()

template<typename _Tp, typename _Sequence = vector<_Tp>, typename _Compare = less<typename _Sequence::value_type>>

size_type std::priority_queue< _Tp, _Sequence, _Compare >::size ( ) const

inline

Returns the number of elements in the queue.

Definition at line 588 of file stl_queue.h.

top()

template<typename _Tp, typename _Sequence = vector<_Tp>, typename _Compare = less<typename _Sequence::value_type>>

const_reference std::priority_queue< _Tp, _Sequence, _Compare >::top ( ) const

inline

Returns a read-only (constant) reference to the data at the first element of the queue.

Definition at line 596 of file stl_queue.h.

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The documentation for this class was generated from the following file:

• stl_queue.h