nvwa::fc_queue< _Tp, _Alloc > Class Template Reference

Class to represent a fixed-capacity queue. More...

#include <fc_queue.h>

Public Member Functions
	fc_queue (size_type max_size, const allocator_type &alloc=allocator_type())
	Constructor that creates the queue with a maximum size (capacity). More...
	fc_queue (const fc_queue &rhs)
	Copy-constructor that copies all elements from another queue. More...
	~fc_queue ()
	Destructor. More...
fc_queue &	operator= (const fc_queue &rhs)
	Assignment operator that copies all elements from another queue. More...
bool	empty () const noexcept
	Checks whether the queue is empty (containing no elements). More...
bool	full () const noexcept
	Checks whether the queue is full (containing the maximum allowed elements). More...
size_type	capacity () const noexcept
	Gets the maximum number of allowed elements in the queue. More...
size_type	size () const noexcept
	Gets the number of existing elements in the queue. More...
reference	front ()
	Gets the first element in the queue. More...
const_reference	front () const
	Gets the first element in the queue. More...
reference	back ()
	Gets the last element in the queue. More...
const_reference	back () const
	Gets the last element in the queue. More...
void	push (const value_type &value)
	Inserts a new element at the end of the queue. More...
void	pop ()
	Discards the first element in the queue. More...
bool	contains (const value_type &value) const
	Checks whether the queue contains a specific element. More...
void	swap (fc_queue &rhs)
	Exchanges the elements of two queues. More...
allocator_type	get_allocator () const
	Gets the allocator of the queue. More...

Detailed Description

template<class _Tp, class _Alloc = std::allocator<_Tp>>
class nvwa::fc_queue< _Tp, _Alloc >

Class to represent a fixed-capacity queue.

This class has an interface close to std::queue, but it allows very efficient and lockless one-producer, one-consumer access, as long as the producer does not try to queue an element when the queue is already full.

Parameters

_Tp	the type of elements in the queue
_Alloc	allocator to use for memory management

Precondition

_Tp shall be CopyConstructible and Destructible, and _Alloc shall meet the allocator requirements (Table 28 in the C++11 spec).

Constructor & Destructor Documentation

fc_queue() [1/2]

template<class _Tp, class _Alloc = std::allocator<_Tp>>

nvwa::fc_queue< _Tp, _Alloc >::fc_queue ( size_type  max_size, const allocator_type &  alloc = allocator_type()  )

inlineexplicit

Constructor that creates the queue with a maximum size (capacity).

Parameters

max_size	the maximum size allowed
alloc	the allocator to use

Precondition

max_size shall be not be zero.

Postcondition

Unless memory allocation throws an exception, this queue will be constructed with the specified maximum size, and the following conditions will hold:

• empty()
• ! full()
• capacity() == max_size
• size() == 0
• get_allocator() == alloc

fc_queue() [2/2]

template<class _Tp , class _Alloc >

nvwa::fc_queue< _Tp, _Alloc >::fc_queue

(

const fc_queue< _Tp, _Alloc > &

rhs

)

Copy-constructor that copies all elements from another queue.

Parameters

rhs	the queue to copy

Postcondition

If copy-construction is successful (no exception is thrown during memory allocation and element copy), this queue will have the same elements as rhs.

~fc_queue()

template<class _Tp, class _Alloc = std::allocator<_Tp>>

nvwa::fc_queue< _Tp, _Alloc >::~fc_queue ( )

inline

Destructor.

It erases all elements and frees memory.

Member Function Documentation

back() [1/2]

template<class _Tp, class _Alloc = std::allocator<_Tp>>

reference nvwa::fc_queue< _Tp, _Alloc >::back ( )

inline

Gets the last element in the queue.

Returns

reference to the last element

back() [2/2]

template<class _Tp, class _Alloc = std::allocator<_Tp>>

const_reference nvwa::fc_queue< _Tp, _Alloc >::back ( ) const

inline

Gets the last element in the queue.

Returns

const reference to the last element

capacity()

template<class _Tp, class _Alloc = std::allocator<_Tp>>

size_type nvwa::fc_queue< _Tp, _Alloc >::capacity ( ) const

inlinenoexcept

Gets the maximum number of allowed elements in the queue.

Returns

the maximum number of allowed elements in the queue

contains()

template<class _Tp, class _Alloc = std::allocator<_Tp>>

bool nvwa::fc_queue< _Tp, _Alloc >::contains ( const value_type &  value ) const

inline

Checks whether the queue contains a specific element.

Parameters

value

the value to be compared

Precondition

value_type shall be EqualityComparable.

Returns

true if found; false otherwise

empty()

template<class _Tp, class _Alloc = std::allocator<_Tp>>

bool nvwa::fc_queue< _Tp, _Alloc >::empty ( ) const

inlinenoexcept

Checks whether the queue is empty (containing no elements).

Returns

true if it is empty; false otherwise

front() [1/2]

template<class _Tp, class _Alloc = std::allocator<_Tp>>

reference nvwa::fc_queue< _Tp, _Alloc >::front ( )

inline

Gets the first element in the queue.

Returns

reference to the first element

front() [2/2]

template<class _Tp, class _Alloc = std::allocator<_Tp>>

const_reference nvwa::fc_queue< _Tp, _Alloc >::front ( ) const

inline

Gets the first element in the queue.

Returns

const reference to the first element

full()

template<class _Tp, class _Alloc = std::allocator<_Tp>>

bool nvwa::fc_queue< _Tp, _Alloc >::full ( ) const

inlinenoexcept

Checks whether the queue is full (containing the maximum allowed elements).

Returns

true if it is full; false otherwise

get_allocator()

template<class _Tp, class _Alloc = std::allocator<_Tp>>

allocator_type nvwa::fc_queue< _Tp, _Alloc >::get_allocator ( ) const

inline

Gets the allocator of the queue.

Returns

the allocator of the queue

operator=()

template<class _Tp, class _Alloc = std::allocator<_Tp>>

fc_queue& nvwa::fc_queue< _Tp, _Alloc >::operator= ( const fc_queue< _Tp, _Alloc > &  rhs )

inline

Assignment operator that copies all elements from another queue.

Parameters

rhs	the queue to copy

Postcondition

If assignment is successful (no exception is thrown during memory allocation and element copy), this queue will have the same elements as rhs. Otherwise this queue is unchanged (strong exception safety is guaranteed).

pop()

template<class _Tp, class _Alloc = std::allocator<_Tp>>

void nvwa::fc_queue< _Tp, _Alloc >::pop ( )

inline

Discards the first element in the queue.

Precondition

This queue is not empty.

Postcondition

One element is discarded at the front, size() is decremented by one, and full() is false.

push()

template<class _Tp, class _Alloc = std::allocator<_Tp>>

void nvwa::fc_queue< _Tp, _Alloc >::push ( const value_type &  value )

inline

Inserts a new element at the end of the queue.

The first element will be discarded if the queue is full.

Parameters

value

the value to be inserted

Postcondition

size() <= capacity() && back() == value, unless an exception is thrown, in which case this queue is unchanged (strong exception safety is guaranteed).

size()

template<class _Tp, class _Alloc = std::allocator<_Tp>>

size_type nvwa::fc_queue< _Tp, _Alloc >::size ( ) const

inlinenoexcept

Gets the number of existing elements in the queue.

Returns

the number of existing elements in the queue

swap()

template<class _Tp, class _Alloc = std::allocator<_Tp>>

void nvwa::fc_queue< _Tp, _Alloc >::swap ( fc_queue< _Tp, _Alloc > &  rhs )

inline

Exchanges the elements of two queues.

Parameters

rhs	the queue to exchange with

Postcondition

If swapping the allocators does not throw, *this will be swapped with rhs. If swapping the allocators throws with strong exception safety guarantee, this function will also provide such guarantee.

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

• fc_queue.h