A C++ template library for embedded applications
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queue


A fixed capacity queue.
STL equivalent: std::queue

etl::queue<typename T,
           const size_t SIZE,
           const size_t MEMORY_MODEL = etl::memory_model::MEMORY_MODEL_LARGE>

Inherits from etl::iqueue<T>
etl::iqueue may be used as a size independent pointer or reference type for any etl::queue instance.

The memory model determines the type used internally for indexes and size, to allow for the most efficient
implementation for the application.

Maximum queue sizes:
MEMORY_MODEL_SMALL   255
MEMORY_MODEL_MEDIUM  65535
MEMORY_MODEL_LARGE   2147483647
MEMORY_MODEL_HUGE    9223372036854775807

See memory_model.h

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Member types


value_type      T
size_type       <based on memory model>
pointer         value_type*
const_pointer   const value_type*
reference       value_type&
const_reference const value_type&

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Constructor


etl::queue<typename T, const size_t SIZE>();

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Element access


T& front()
const T& front() const

Returns a reference or const reference to the first element.
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T& back()
const T& back() const

Returns a reference or const reference to the last element.

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Capacity


bool empty() const

Returns true if the size of the queue is zero, otherwise false.
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bool full() const

Returns true if the size of the queue is SIZE, otherwise false.
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size_type size() const

Returns the size of the queue.
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size_type available() const

Returns the remaining available capacity in the queue.
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ETL_CONSTEXPR size_type max_size() const

Returns the maximum possible size of the queue.
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ETL_CONSTEXPR size_type capacity() const

Returns the maximum possible size of the queue.

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Modifiers


void push(parameter_t value);

Pushes a value to the back of the queue.
Emits an etl::queue_full if the queue is full and ETL_CHECK_PUSH_POP is defined. If asserts or exceptions are not
enabled then undefined behaviour occurs.
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C++03

void emplace(const T1& value1);
void emplace(const T1& value1, const T2& value2);
void emplace(const T1& value1, const T2& value2, const T3& value3);
void emplace(const T1& value1, const T2& value2, const T3& value3, const T4& value4);

C++11

void emplace(Args&&… args);

Constructs an item in the the queue 'in place'.
C++03: Supports up to four constructor parameters.
Emits an etl::queue_full if the queue is full and ETL_CHECK_PUSH_POP is defined. If asserts or exceptions are not
enabled then undefined behaviour occurs.
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void pop();

Pop a value from the front of the list.
Emits an etl::queue_empty if the queue is empty and ETL_CHECK_PUSH_POP is defined. Undefined behaviour if the
queue is empty.
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void pop_into(TContainer& destination);

Pop a value from the front of the list and places it in destination.
Emits an etl::queue_empty if the queue is empty and ETL_CHECK_PUSH_POP is defined. Undefined behaviour if the
queue is empty.
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void clear();

Clears the queue to a size of zero.
queue.h