Difference between revisions of "cpp/container/queue"
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class Container {{=}} std::deque<T> | class Container {{=}} std::deque<T> | ||
> class queue; | > class queue; | ||
| − | }} | + | }} |
The {{tt|std::queue}} class is a container adapter that gives the programmer the functionality of a queue - specifically, a FIFO (first-in, first-out) data structure. | The {{tt|std::queue}} class is a container adapter that gives the programmer the functionality of a queue - specifically, a FIFO (first-in, first-out) data structure. | ||
| − | The class template acts as a wrapper to the underlying container - only a specific set of functions is provided. The queue pushes the elements on the back of the underlying container and pops them from the front. | + | The class template acts as a wrapper to the underlying container - only a specific set of functions is provided. The queue pushes the elements on the back of the underlying container and pops them from the front. |
===Template parameters=== | ===Template parameters=== | ||
| − | {{par begin}} | + | {{par begin}} |
| − | {{par | T | The type of the stored elements.}} | + | {{par | T | The type of the stored elements. {{rev inl|since=c++17|The behavior is undefined if {{tt|T}} is not the same type as {{tt|Container::value_type}}.}} }} |
{{par | Container | The type of the underlying container to use to store the elements. The container must satisfy the requirements of {{concept|SequenceContainer}}. Additionally, it must provide the following functions with the usual semantics: | {{par | Container | The type of the underlying container to use to store the elements. The container must satisfy the requirements of {{concept|SequenceContainer}}. Additionally, it must provide the following functions with the usual semantics: | ||
| − | * {{tt|back()}} | + | * {{tt|back()}} |
| − | * {{tt|front()}} | + | * {{tt|front()}} |
| − | * {{tt|push_back()}} | + | * {{tt|push_back()}} |
* {{tt|pop_front()}} | * {{tt|pop_front()}} | ||
Revision as of 13:16, 25 February 2017
| Defined in header <queue>
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| template< class T, |
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The std::queue class is a container adapter that gives the programmer the functionality of a queue - specifically, a FIFO (first-in, first-out) data structure.
The class template acts as a wrapper to the underlying container - only a specific set of functions is provided. The queue pushes the elements on the back of the underlying container and pops them from the front.
Contents |
Template parameters
| T | - | The type of the stored elements. The behavior is undefined if T is not the same type as Container::value_type.(since C++17)
|
| Container | - | The type of the underlying container to use to store the elements. The container must satisfy the requirements of Template:concept. Additionally, it must provide the following functions with the usual semantics:
The standard containers std::deque and std::list satisfy these requirements. |
Member types
| Member type | Definition |
container_type
|
Container
|
value_type
|
Container::value_type
|
size_type
|
Container::size_type |
reference
|
Container::reference
|
const_reference
|
Container::const_reference
|
Member functions
constructs the queue (public member function) | |
destructs the queue (public member function) | |
| assigns values to the container adaptor (public member function) | |
Element access | |
| access the first element (public member function) | |
| access the last element (public member function) | |
Capacity | |
| checks whether the container adaptor is empty (public member function) | |
| returns the number of elements (public member function) | |
Modifiers | |
| inserts element at the end (public member function) | |
| (C++11) |
constructs element in-place at the end (public member function) |
| removes the first element (public member function) | |
| (C++11) |
swaps the contents (public member function) |
Member objects | |
| Container c |
the underlying container (protected member object) |
Non-member functions
lexicographically compares the values of two queues (function template) | |
| (C++11) |
specializes the std::swap algorithm (function template) |
Helper classes
| specializes the std::uses_allocator type trait (class template specialization) |
