mirror of
https://github.com/ETLCPP/etl.git
synced 2026-06-16 00:46:03 +08:00
293 lines
6.1 KiB
Markdown
293 lines
6.1 KiB
Markdown
---
|
|
title: "circular_buffer"
|
|
---
|
|
|
|
{{< callout >}}
|
|
Header: `circular_buffer.h`
|
|
{{< /callout >}}
|
|
|
|
A fixed capacity circular buffer.
|
|
|
|
```cpp
|
|
etl::circular_buffer<typename T, size_t SIZE>
|
|
etl::circular_buffer_ext<typename T>
|
|
```
|
|
|
|
Inherits from `etl::icircular_buffer<T>`
|
|
`etl::icircular_buffer` may be used as a size independent pointer or reference type for any `etl::circular_buffer` instance.
|
|
|
|
## External buffer
|
|
|
|
```cpp
|
|
etl::circular_buffer_ext<typename T>
|
|
```
|
|
For this template the constructor expects pointer and size parameters to the externally provided buffer. This buffer must not be shared concurrently with any other container.
|
|
When a `circular_buffer` with an external buffer is moved, the data is moved, not the pointer to the buffer.
|
|
The external buffer MUST be declared one item larger that the intended capacity of the circular buffer.
|
|
|
|
A swap on a `circular_buffer` with an external buffer is fast as it will swap buffer pointers rather than copying items.
|
|
|
|
## Template deduction guides
|
|
```cpp
|
|
template <typename T, typename... Ts>
|
|
etl::circular_buffer(T, Ts...)
|
|
-> etl::circular_buffer<T, 1U + sizeof...(Ts)>;
|
|
```
|
|
C++17 and above.
|
|
Only enabled if `Ts...` is the same type as `T`.
|
|
|
|
### Example
|
|
```cpp
|
|
etl::circular_buffer data{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
|
|
```
|
|
|
|
Defines data as a `circular_buffer` of `int`, of length `10`, containing the supplied data.
|
|
|
|
## Member types
|
|
|
|
```cpp
|
|
value_type T
|
|
size_type std::size_t
|
|
difference_type std::ptrdiff_t
|
|
reference value_type&
|
|
const_reference const value_type&
|
|
rvalue_reference value_type&&
|
|
pointer value_type*
|
|
const_pointer const value_type*
|
|
iterator Random access iterator
|
|
const_iterator Constant random access iterator
|
|
reverse_iterator reverse_iterator<iterator>
|
|
const_reverse_iterator reverse_iterator<const_iterator>
|
|
```
|
|
|
|
## Static Constants
|
|
|
|
`MAX_SIZE` The maximum size of the circular_buffer.
|
|
|
|
## Constructors
|
|
|
|
```cpp
|
|
circular_buffer<typename T, size_t SIZE>();
|
|
|
|
circular_buffer<typename T, size_t SIZE>(const etl::circular_buffer<typename T, size_t SIZE>& other);
|
|
|
|
circular_buffer<typename T, size_t SIZE>(etl::circular_buffer<typename T, size_t SIZE>&& other);
|
|
```
|
|
|
|
---
|
|
|
|
```cpp
|
|
circular_buffer_ext(void* buffer, size_t max_size)
|
|
|
|
circular_buffer_ext(size_t max_size) 20.32.1
|
|
|
|
template <typename TIterator>
|
|
circular_buffer_ext(TIterator first, const TIterator& last, void* buffer, size_t max_size)
|
|
|
|
circular_buffer_ext(std::initializer_list<T> init, void* buffer, size_t max_size)
|
|
|
|
circular_buffer_ext(const circular_buffer_ext& other, void* buffer, size_t max_size)
|
|
```
|
|
|
|
## Status
|
|
|
|
```cpp
|
|
bool is_valid() const
|
|
```
|
|
**Description**
|
|
Returns `true` if the buffer has been set through the constructor or `set_buffer`.
|
|
For circular_buffer_ext only.
|
|
Since: `20.32.1`
|
|
|
|
## Element access
|
|
|
|
```cpp
|
|
reference operator[](size_t i)
|
|
const_reference operator[](size_t i) const
|
|
```
|
|
**Description**
|
|
Returns a reference or const reference to the indexed element.
|
|
|
|
---
|
|
|
|
```cpp
|
|
reference front()
|
|
const_reference front() const
|
|
```
|
|
**Description**
|
|
Returns a reference or const reference to the first element.
|
|
|
|
---
|
|
|
|
```cpp
|
|
reference back()
|
|
const_reference back() const
|
|
```
|
|
**Description**
|
|
Returns a reference or const reference to the last element.
|
|
|
|
---
|
|
|
|
```cpp
|
|
void fill(value_type value)
|
|
```
|
|
**Description**
|
|
Fill the current size of the buffer with `value`.
|
|
Since: `20.24.0`
|
|
|
|
## Iterators
|
|
|
|
```cpp
|
|
iterator begin()
|
|
const_iterator begin() const
|
|
const_iterator cbegin() const
|
|
```
|
|
**Description**
|
|
Returns an iterator to the beginning of the `circular_buffer`.
|
|
|
|
---
|
|
|
|
```cpp
|
|
iterator end()
|
|
const_iterator end() const
|
|
const_iterator cend() const
|
|
```
|
|
**Description**
|
|
Returns an iterator to the end of the `circular_buffer`.
|
|
|
|
---
|
|
|
|
```cpp
|
|
iterator rbegin()
|
|
const_reverse_iterator rbegin() const
|
|
const_reverse_iterator crbegin() const
|
|
```
|
|
**Description**
|
|
Returns a reverse iterator to the beginning of the `circular_buffer`.
|
|
|
|
---
|
|
|
|
```cpp
|
|
iterator rend()
|
|
const_reverse_iterator rend() const
|
|
const_reverse_iterator crend() const
|
|
```
|
|
**Description**
|
|
Returns a reverse iterator to the end of the `circular_buffer`.
|
|
|
|
## Capacity
|
|
|
|
```cpp
|
|
bool empty() const
|
|
```
|
|
**Description**
|
|
Returns `true` if the size of the circular_buffer is zero, otherwise `false`.
|
|
|
|
---
|
|
|
|
```cpp
|
|
bool full() const
|
|
```
|
|
**Description**
|
|
Returns `true` if the size of the circular_buffer is `SIZE`, otherwise `false`.
|
|
|
|
---
|
|
|
|
```cpp
|
|
size_t size() const
|
|
```
|
|
**Description**
|
|
Returns the size of the `circular_buffer`.
|
|
|
|
---
|
|
|
|
```cpp
|
|
size_t max_size() const
|
|
```
|
|
**Description**
|
|
Returns the maximum possible size of the `circular_buffer`.
|
|
|
|
---
|
|
|
|
```cpp
|
|
size_t capacity() const
|
|
```
|
|
**Description**
|
|
Returns the maximum possible size of the `circular_buffer`.
|
|
|
|
---
|
|
|
|
```cpp
|
|
size_t available() const
|
|
```
|
|
**Description**
|
|
Returns the remaining available capacity in the `circular_buffer`.
|
|
|
|
## Modifiers
|
|
|
|
```cpp
|
|
void set_buffer(void* buffer)
|
|
```
|
|
**Description**
|
|
Sets the associated buffer.
|
|
For circular_buffer_ext only.
|
|
Since: `20.32.1`
|
|
|
|
---
|
|
|
|
```cpp
|
|
void push(const_reference value)
|
|
void push(rvalue_reference value)
|
|
```
|
|
**Description**
|
|
Pushes a value to the back of the `circular_buffer`.
|
|
|
|
---
|
|
|
|
```cpp
|
|
template <typename TIterator>
|
|
void push(TIterator first, const TIterator& last)
|
|
```
|
|
**Description**
|
|
Pushes values to the back of the `circular_buffer`.
|
|
|
|
---
|
|
|
|
```cpp
|
|
void pop()
|
|
```
|
|
**Description**
|
|
Pop a value from the front of the `circular_buffer`.
|
|
|
|
---
|
|
|
|
```cpp
|
|
void clear()
|
|
```
|
|
**Description**
|
|
Clears the circular_buffer to a size of zero.
|
|
|
|
---
|
|
|
|
```cpp
|
|
void swap(circular_buffer<T, SIZE>& other)
|
|
```
|
|
**Description**
|
|
Swaps the `circular_buffer` with `other`.
|
|
|
|
---
|
|
|
|
```cpp
|
|
void swap(circular_buffer_ext<T> other)
|
|
```
|
|
**Description**
|
|
Swaps the `circular_buffer_ext` with `other`.
|
|
The internal pointers to the external buffers are swapped.
|
|
|
|
## Non-member functions
|
|
|
|
`==` `true` if the contents of the vectors are equal, otherwise `false`.
|
|
`!=` `true` if the contents of the vectors are not equal, otherwise `false`.
|
|
|
|
`swap` Swaps two circular buffers. A circular buffer with internal storage copies items, while one with an external buffer will swap pointers.
|