std::queue (3) - Linux Manuals

std::queue: std::queue


std::queue - std::queue


Defined in header <queue>
class T,
class Container = std::deque<T>
> class queue;

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.

Template parameters

            The type of the stored elements.
T - The behavior is undefined if T is not the same type as Container::value_type.
            (since C++17)
            The type of the underlying container to use to store the elements. The container must satisfy the requirements of SequenceContainer. Additionally, it must provide the following functions with the usual semantics:

            * back()
Container - * front()
            * push_back()
            * pop_front()

            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
constructor (public member function)
              destructs the queue
destructor (public member function)
              assigns values to the container adaptor
operator= (public member function)

Element access

              access the first element
front (public member function)
              access the last element
back (public member function)


              checks whether the underlying container is empty
empty (public member function)
              returns the number of elements
size (public member function)


              inserts element at the end
push (public member function)

emplace constructs element in-place at the end
              (public member function)
              removes the first element
pop (public member function)
              swaps the contents
swap (public member function)

Member objects

              the underlying container
Container c (protected member object)

Non-member functions

operator!= lexicographically compares the values in the queue
operator< (function template)
                      specializes the std::swap algorithm
std::swap(std::queue) (function template)

Helper classes

std::uses_allocator<std::queue> specializes the std::uses_allocator type trait
                                (function template)

Deduction_guides(since C++17)