A simple list of objects of type <T> that is intended to be used as a circular buffer (eg, a FIFO) when the alloc/free overhead associated with a linked-list approach is to be avoided. More...

Classes
class	const_iterator
	A simple forward const iterator for a circular buffer. More...

Public Types
typedef T	value_type
	The value type the list contains. More...

typedef T *	pointer
	The pointer type for non-const access to value_type items. More...

typedef const T *	const_pointer
	The pointer type for const access to value_type items. More...

typedef T &	reference
	The type used for storing into value_type objects. More...

typedef const T &	const_reference
	The type used for reading from constant value_type objects. More...

typedef label	size_type
	The type to represent the size of a buffer. More...

typedef label	difference_type
	The difference between iterator objects. More...

Public Member Functions
constexpr	CircularBuffer () noexcept
	Default construct, empty buffer without allocation. More...

	CircularBuffer (const label len)
	Construct an empty buffer with given reserve size. More...

	CircularBuffer (const CircularBuffer< T > &list)
	Copy construct. More...

	CircularBuffer (CircularBuffer< T > &&list)
	Move construct. More...

	CircularBuffer (Istream &is)
	Construct from Istream - uses readList. More...

label	capacity () const noexcept
	Size of the underlying storage. More...

bool	empty () const noexcept
	Empty or exhausted buffer. More...

label	size () const noexcept
	The current number of buffer items. More...

label	space () const noexcept
	The nominal space available to fill. Subtract 1 for the number to append before re-balancing is needed. More...

labelRange	range_one () const noexcept
	The addressing range covered by array_one() More...

labelRange	range_two () const noexcept
	The addressing range covered by array_two() More...

SubList< T >	array_one ()
	The contents of the first internal array. More...

SubList< T >	array_two ()
	The contents of the second internal array. More...

const SubList< T >	array_one () const
	The contents of the first internal array. More...

const SubList< T >	array_two () const
	The contents of the second internal array. More...

T &	front ()
	Access the first element (front). Requires !empty(). More...

T &	back ()
	Access the last element (back). Requires !empty(). More...

const T &	front () const
	Const access to the first element (front). Requires !empty(). More...

const T &	back () const
	Const access to the last element (back). Requires !empty(). More...

void	reserve (const label len)
	Reserve allocation space for at least this size, allocating new space if required and retaining old content. More...

void	reserve_nocopy (const label len)
	Reserve allocation space for at least this size, allocating new space if required without retaining old content. More...

void	clear () noexcept
	Clear the addressed buffer, does not change allocation. More...

void	clearStorage ()
	Clear the buffer and delete storage. More...

void	swap (CircularBuffer< T > &other)
	Swap content, independent of sizing parameter. More...

bool	contains (const T &val) const
	True if the value is contained in the list. More...

bool	contains (const T &val, label pos) const
	Is the value contained in the list? More...

label	find (const T &val, label pos=0) const
	Find index of the first occurrence of the value. More...

void	push_front (const T &val)
	Copy prepend an element to the front of the buffer. More...

void	push_front (T &&val)
	Move prepend an element to the front of the buffer. More...

template<class... Args>
T &	emplace_front (Args &&... args)
	Construct an element at the front of the buffer, return reference to the new element. More...

void	push_back (const T &val)
	Copy append an element to the end of the buffer. More...

void	push_back (T &&val)
	Move append an element to the end of the buffer. More...

template<class... Args>
T &	emplace_back (Args &&... args)
	Construct an element at the end of the buffer, return reference to the new element. More...

void	pop_front (label n=1)
	Shrink by moving the front of the buffer 1 or more times. More...

void	pop_back (label n=1)
	Shrink by moving the end of the buffer 1 or more times. More...

void	push_back (const UList< T > &list)
	Copy append multiple elements the end of the buffer. More...

template<class Addr >
void	push_back (const IndirectListBase< T, Addr > &list)
	Copy append IndirectList elements the end of the buffer. More...

label	push_uniq (const T &val)
	Append an element if not already in the buffer. More...

List< T >	list () const
	Return a copy of the buffer flattened into a single List. Use sparingly! More...

void	reverse ()
	Reverse the buffer order, swapping elements. More...

T &	operator[] (const label i)
	Non-const access to an element in the list. More...

const T &	operator[] (const label i) const
	Const access to an element in the list. More...

void	operator= (const CircularBuffer< T > &list)
	Copy construct. More...

void	operator= (CircularBuffer< T > &&list)
	Move construct. More...

void	operator= (const T &val)
	Assign all addressed elements to the given value. More...

void	operator= (const Foam::zero)
	Assignment of all entries to zero. More...

void	operator= (const UList< T > &rhs)
	Deep copy values from a list of the addressed elements. More...

template<class AnyAddr >
void	operator= (const IndirectListBase< T, AnyAddr > &rhs)
	Deep copy values from a list of the addressed elements. More...

Ostream &	info (Ostream &os) const
	Print information. More...

Istream &	readList (Istream &is)
	Read buffer contents from Istream. More...

Ostream &	writeList (Ostream &os, const label shortLen=0) const
	Write buffer contents with line-breaks in ASCII when length exceeds shortLen. More...

const_iterator	cbegin () const
	Return a const_iterator at begin of buffer. More...

const_iterator	cend () const
	Return a const_iterator at end of buffer. More...

const_iterator	begin () const
	Return a const_iterator at begin of buffer. More...

const_iterator	end () const
	Return a const_iterator at end of buffer. More...

Static Public Member Functions
static constexpr label	min_size () noexcept
	Lower capacity limit. More...

Friends
Istream &	operator>> (Istream &is, CircularBuffer< T > &list)
	Use the readList() method to read contents from Istream. More...

Ostream &	operator (Ostream &os, const CircularBuffer< T > &list)
	Write to Ostream. More...

Detailed Description

template<class T>
class Foam::CircularBuffer< T >

A simple list of objects of type <T> that is intended to be used as a circular buffer (eg, a FIFO) when the alloc/free overhead associated with a linked-list approach is to be avoided.

The internal storage is addressed by independent begin/end markers.

The begin marker points to the front.
The end marker is a one-past the back.

This results in a variety ofr different possible buffer states:

empty (begin == end)

simple/linear (begin < end) has no wrapping:

   |.|.|.|a|b|c|d|.|.|.|
   beg ___^
   end ___________^

split (begin > end):

   |f|g|h|i|.|.|.|a|b|c|d|e|
   end _____^
   beg ___________^

The methods range_one(), range_two() return the internal indexing and the methods array_one(), array_two() provide direct access to the internal contents.

When filling the buffer, the internal storage will be resized (doubling strategy) as required. When this occurs, the new list will be linearized with begin = 0.

Simultaneously when filling, the storage buffer will be over-allocated to avoid ambiguity when (begin == end), which represents an empty buffer and not a full buffer. Eg,

    |c|d|.|a|b|
    end _^
    beg ___^

after appending one more, it would be incorrect to simply fill the available space:

    |c|d|e|a|b|
    end ___^        WRONG : would represent empty!
    beg ___^

the storage is instead increased (doubled) and rebalanced before the append occurs (old capacity 5, new capacity 10):

    |a|b|c|d|e|.|.|.|.|.|
    _^_ beg
    end _______^

Source files

Definition at line 102 of file CircularBuffer.H.

Member Typedef Documentation

◆ value_type

typedef T value_type

The value type the list contains.

Definition at line 175 of file CircularBuffer.H.

◆ pointer

typedef T* pointer

The pointer type for non-const access to value_type items.

Definition at line 180 of file CircularBuffer.H.

◆ const_pointer

typedef const T* const_pointer

The pointer type for const access to value_type items.

Definition at line 185 of file CircularBuffer.H.

◆ reference

typedef T& reference

The type used for storing into value_type objects.

Definition at line 190 of file CircularBuffer.H.

◆ const_reference

typedef const T& const_reference

The type used for reading from constant value_type objects.

Definition at line 195 of file CircularBuffer.H.

◆ size_type

typedef label size_type

The type to represent the size of a buffer.

Definition at line 200 of file CircularBuffer.H.

◆ difference_type

typedef label difference_type

The difference between iterator objects.

Definition at line 205 of file CircularBuffer.H.

Constructor & Destructor Documentation

◆ CircularBuffer() [1/5]

constexpr CircularBuffer ( )

inlinenoexcept

Default construct, empty buffer without allocation.

Definition at line 107 of file CircularBufferI.H.

◆ CircularBuffer() [2/5]

CircularBuffer ( const label len )

inlineexplicit

Construct an empty buffer with given reserve size.

Definition at line 116 of file CircularBufferI.H.

◆ CircularBuffer() [3/5]

CircularBuffer ( const CircularBuffer< T > & list )

inline

Copy construct.

Definition at line 126 of file CircularBufferI.H.

◆ CircularBuffer() [4/5]

CircularBuffer ( CircularBuffer< T > && list )

inline

Move construct.

Definition at line 138 of file CircularBufferI.H.

◆ CircularBuffer() [5/5]

CircularBuffer ( Istream & is )

explicit

Construct from Istream - uses readList.

Definition at line 28 of file CircularBufferIO.C.

Member Function Documentation

◆ min_size()

static constexpr label min_size ( )

inlinestaticnoexcept

Lower capacity limit.

Definition at line 248 of file CircularBuffer.H.

◆ capacity()

Foam::label capacity ( ) const

inlinenoexcept

Size of the underlying storage.

Definition at line 154 of file CircularBufferI.H.

◆ empty()

bool empty ( ) const

inlinenoexcept

Empty or exhausted buffer.

Definition at line 162 of file CircularBufferI.H.

Referenced by Foam::meshTools::bandCompression().

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◆ size()

Foam::label size ( ) const

inlinenoexcept

The current number of buffer items.

Definition at line 169 of file CircularBufferI.H.

References Foam::diff().

Referenced by CircularBuffer< T >::cend(), and Foam::polyMeshZipUpCells().

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◆ space()

Foam::label space ( ) const

inlinenoexcept

The nominal space available to fill. Subtract 1 for the number to append before re-balancing is needed.

Definition at line 183 of file CircularBufferI.H.

◆ range_one()

Foam::labelRange range_one ( ) const

inlinenoexcept

The addressing range covered by array_one()

Definition at line 190 of file CircularBufferI.H.

◆ range_two()

Foam::labelRange range_two ( ) const

inlinenoexcept

The addressing range covered by array_two()

Definition at line 202 of file CircularBufferI.H.

◆ array_one() [1/2]

Foam::SubList< T > array_one ( )

The contents of the first internal array.

Definition at line 70 of file CircularBuffer.C.

Referenced by CircularBuffer< T >::operator=().

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◆ array_two() [1/2]

Foam::SubList< T > array_two ( )

The contents of the second internal array.

Definition at line 78 of file CircularBuffer.C.

Referenced by CircularBuffer< T >::operator=().

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◆ array_one() [2/2]

const Foam::SubList< T > array_one ( ) const

The contents of the first internal array.

Definition at line 86 of file CircularBuffer.C.

◆ array_two() [2/2]

const Foam::SubList< T > array_two ( ) const

The contents of the second internal array.

Definition at line 94 of file CircularBuffer.C.

◆ front() [1/2]

T & front ( )

inline

Access the first element (front). Requires !empty().

Definition at line 267 of file CircularBufferI.H.

References Foam::abort(), Foam::FatalError, and FatalErrorInFunction.

Referenced by Foam::meshTools::bandCompression(), and Foam::polyMeshZipUpCells().

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◆ back() [1/2]

T & back ( )

inline

Access the last element (back). Requires !empty().

Definition at line 291 of file CircularBufferI.H.

References Foam::abort(), Foam::FatalError, and FatalErrorInFunction.

Referenced by Foam::polyMeshZipUpCells().

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◆ front() [2/2]

const T & front ( ) const

inline

Const access to the first element (front). Requires !empty().

Definition at line 279 of file CircularBufferI.H.

References Foam::abort(), Foam::FatalError, and FatalErrorInFunction.

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◆ back() [2/2]

const T & back ( ) const

inline

Const access to the last element (back). Requires !empty().

Definition at line 303 of file CircularBufferI.H.

References Foam::abort(), Foam::FatalError, and FatalErrorInFunction.

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◆ reserve()

void reserve ( const label len )

inline

Reserve allocation space for at least this size, allocating new space if required and retaining old content.

Never shrinks.

Definition at line 239 of file CircularBufferI.H.

◆ reserve_nocopy()

void reserve_nocopy ( const label len )

inline

Reserve allocation space for at least this size, allocating new space if required without retaining old content.

Never shrinks.

Definition at line 246 of file CircularBufferI.H.

◆ clear()

void clear ( )

inlinenoexcept

Clear the addressed buffer, does not change allocation.

Definition at line 209 of file CircularBufferI.H.

Referenced by Foam::polyMeshZipUpCells().

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◆ clearStorage()

void clearStorage ( )

inline

Clear the buffer and delete storage.

Definition at line 216 of file CircularBufferI.H.

◆ swap()

void swap ( CircularBuffer< T > & other )

inline

Swap content, independent of sizing parameter.

Definition at line 224 of file CircularBufferI.H.

◆ contains() [1/2]

bool contains ( const T & val ) const

inline

True if the value is contained in the list.

Definition at line 253 of file CircularBufferI.H.

◆ contains() [2/2]

bool contains	(	const T &	val,
		label	pos
	)		const

inline

Is the value contained in the list?

Parameters

val	The value to search for
pos	The first position to examine (no-op if -ve)

Returns: true if found.

Definition at line 260 of file CircularBufferI.H.

References Foam::ListOps::find(), and Foam::pos().

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◆ find()

Foam::label find	(	const T &	val,
		label	pos = `0`
	)		const

Find index of the first occurrence of the value.

Any occurrences before the start pos are ignored. Linear search.

Returns: position in list or -1 if not found.

Definition at line 102 of file CircularBuffer.C.

References Foam::pos().

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◆ push_front() [1/2]

void push_front ( const T & val )

inline

Copy prepend an element to the front of the buffer.

Definition at line 315 of file CircularBufferI.H.

References reserve().

Referenced by Foam::polyMeshZipUpCells().

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◆ push_front() [2/2]

void push_front ( T && val )

inline

Move prepend an element to the front of the buffer.

Definition at line 327 of file CircularBufferI.H.

References reserve().

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◆ emplace_front()

T & emplace_front ( Args &&... args )

inline

Construct an element at the front of the buffer, return reference to the new element.

Definition at line 340 of file CircularBufferI.H.

References args, reserve(), and Foam::T().

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◆ push_back() [1/4]

void push_back ( const T & val )

inline

Copy append an element to the end of the buffer.

Definition at line 354 of file CircularBufferI.H.

References reserve().

Referenced by Foam::meshTools::bandCompression(), and Foam::polyMeshZipUpCells().

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◆ push_back() [2/4]

void push_back ( T && val )

inline

Move append an element to the end of the buffer.

Definition at line 366 of file CircularBufferI.H.

References reserve().

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◆ emplace_back()

T & emplace_back ( Args &&... args )

inline

Construct an element at the end of the buffer, return reference to the new element.

Definition at line 379 of file CircularBufferI.H.

References args, reserve(), and Foam::T().

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◆ pop_front()

void pop_front ( label n = 1 )

inline

Shrink by moving the front of the buffer 1 or more times.

Definition at line 394 of file CircularBufferI.H.

References n.

Referenced by Foam::meshTools::bandCompression(), and Foam::polyMeshZipUpCells().

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◆ pop_back()

void pop_back ( label n = 1 )

inline

Shrink by moving the end of the buffer 1 or more times.

Definition at line 411 of file CircularBufferI.H.

References n.

◆ push_back() [3/4]

void push_back ( const UList< T > & list )

inline

Copy append multiple elements the end of the buffer.

Definition at line 443 of file CircularBufferI.H.

References UList< T >::fcIndex(), reserve(), and UList< T >::size().

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◆ push_back() [4/4]

void push_back ( const IndirectListBase< T, Addr > & list )

inline

Copy append IndirectList elements the end of the buffer.

Definition at line 465 of file CircularBufferI.H.

References IndirectListBase< T, Addr >::fcIndex(), reserve(), and IndirectListBase< T, Addr >::size().

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◆ push_uniq()

Foam::label push_uniq ( const T & val )

inline

Append an element if not already in the buffer.

Returns: the change in the buffer length

Definition at line 428 of file CircularBufferI.H.

◆ list()

Foam::List< T > list ( ) const

Return a copy of the buffer flattened into a single List. Use sparingly!

Definition at line 156 of file CircularBuffer.C.

References UList< T >::slice().

Referenced by Foam::polyMeshZipUpCells().

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◆ reverse()

void reverse ( )

Reverse the buffer order, swapping elements.

Definition at line 143 of file CircularBuffer.C.

References n, and Foam::Swap().

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◆ operator[]() [1/2]

T & operator[] ( const label i )

inline

Non-const access to an element in the list.

The index is allowed to wrap in both directions

Definition at line 489 of file CircularBufferI.H.

◆ operator[]() [2/2]

const T & operator[] ( const label i ) const

inline

Const access to an element in the list.

The index is allowed to wrap in both directions

Definition at line 497 of file CircularBufferI.H.

◆ operator=() [1/6]

void operator= ( const CircularBuffer< T > & list )

inline

Copy construct.

Definition at line 505 of file CircularBufferI.H.

References CircularBuffer< T >::array_one(), CircularBuffer< T >::array_two(), clear(), reserve(), and Foam::T().

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◆ operator=() [2/6]

void operator= ( CircularBuffer< T > && list )

inline

Move construct.

Definition at line 542 of file CircularBufferI.H.

◆ operator=() [3/6]

void operator= ( const T & val )

inline

Assign all addressed elements to the given value.

Definition at line 555 of file CircularBufferI.H.

◆ operator=() [4/6]

void operator= ( const Foam::zero )

inline

Assignment of all entries to zero.

Definition at line 563 of file CircularBufferI.H.

◆ operator=() [5/6]

void operator= ( const UList< T > & rhs )

inline

Deep copy values from a list of the addressed elements.

Definition at line 571 of file CircularBufferI.H.

◆ operator=() [6/6]

void operator= ( const IndirectListBase< T, AnyAddr > & rhs )

inline

Deep copy values from a list of the addressed elements.

Definition at line 580 of file CircularBufferI.H.

◆ info()

Foam::Ostream & info ( Ostream & os ) const

Print information.

Definition at line 37 of file CircularBufferIO.C.

References Foam::nl, and os().

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◆ readList()

Foam::Istream & readList ( Istream & is )

Read buffer contents from Istream.

Definition at line 51 of file CircularBufferIO.C.

References DynamicList< T, SizeMin >::capacity(), UList< T >::empty(), DynamicList< T, SizeMin >::readList(), DynamicList< T, SizeMin >::resize(), DynamicList< T, SizeMin >::setCapacity(), and UList< T >::size().

Referenced by Foam::operator>>().

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◆ writeList()

Foam::Ostream & writeList	(	Ostream &	os,
		const label	shortLen = `0`
	)		const

Write buffer contents with line-breaks in ASCII when length exceeds shortLen.

Using '0' suppresses line-breaks entirely.

Definition at line 81 of file CircularBufferIO.C.

References Foam::abort(), Foam::FatalError, FatalErrorInFunction, FUNCTION_NAME, Foam::nl, os(), and T.

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◆ cbegin()

const_iterator cbegin ( ) const

inline

Return a const_iterator at begin of buffer.

Definition at line 620 of file CircularBuffer.H.

Referenced by CircularBuffer< T >::begin().

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◆ cend()

const_iterator cend ( ) const

inline

Return a const_iterator at end of buffer.

Definition at line 628 of file CircularBuffer.H.

References CircularBuffer< T >::size().

Referenced by CircularBuffer< T >::end().

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◆ begin()

const_iterator begin ( ) const

inline

Return a const_iterator at begin of buffer.

Definition at line 636 of file CircularBuffer.H.

References CircularBuffer< T >::cbegin().

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◆ end()

const_iterator end ( ) const

inline

Return a const_iterator at end of buffer.

Definition at line 641 of file CircularBuffer.H.

References CircularBuffer< T >::cend().

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Friends And Related Function Documentation

◆ operator>>

Istream& operator>>	(	Istream &	is,
		CircularBuffer< T > &	list
	)

friend

Use the readList() method to read contents from Istream.

Definition at line 651 of file CircularBuffer.H.

◆ operator

Ostream& operator	(	Ostream &	os,
		const CircularBuffer< T > &	list
	)

friend

Write to Ostream.

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

src/OpenFOAM/containers/Buffers/CircularBuffer.H
src/OpenFOAM/containers/Buffers/CircularBuffer.C
src/OpenFOAM/containers/Buffers/CircularBufferI.H
src/OpenFOAM/containers/Buffers/CircularBufferIO.C

Classes

Public Types

Public Member Functions

Static Public Member Functions

Friends

Detailed Description

template<class T> class Foam::CircularBuffer< T >

Member Typedef Documentation

◆ value_type

◆ pointer

◆ const_pointer

◆ reference

◆ const_reference

◆ size_type

◆ difference_type

Constructor & Destructor Documentation

◆ CircularBuffer() [1/5]

◆ CircularBuffer() [2/5]

◆ CircularBuffer() [3/5]

◆ CircularBuffer() [4/5]

◆ CircularBuffer() [5/5]

Member Function Documentation

◆ min_size()

◆ capacity()

◆ empty()

◆ size()

◆ space()

◆ range_one()

◆ range_two()

◆ array_one() [1/2]

◆ array_two() [1/2]

◆ array_one() [2/2]

◆ array_two() [2/2]

◆ front() [1/2]

◆ back() [1/2]

◆ front() [2/2]

◆ back() [2/2]

◆ reserve()

◆ reserve_nocopy()

◆ clear()

◆ clearStorage()

◆ swap()

◆ contains() [1/2]

◆ contains() [2/2]

◆ find()

◆ push_front() [1/2]

◆ push_front() [2/2]

◆ emplace_front()

◆ push_back() [1/4]

◆ push_back() [2/4]

◆ emplace_back()

◆ pop_front()

◆ pop_back()

◆ push_back() [3/4]

◆ push_back() [4/4]

◆ push_uniq()

◆ list()

◆ reverse()

◆ operator[]() [1/2]

◆ operator[]() [2/2]

◆ operator=() [1/6]

◆ operator=() [2/6]

◆ operator=() [3/6]

◆ operator=() [4/6]

◆ operator=() [5/6]

◆ operator=() [6/6]

◆ info()

◆ readList()

◆ writeList()

◆ cbegin()

◆ cend()

◆ begin()

◆ end()

Friends And Related Function Documentation

◆ operator>>

◆ operator

template<class T>
class Foam::CircularBuffer< T >