std::queue(3)

NAME
std::queue - std::queue

Synopsis
   Defined in header <queue>
   template<
   class T,
   class Container = std::deque<T>
   > class queue;
   The std::queue class is a container adaptor 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:
   Container - * back()
                 * 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
   constructor constructs the queue
                 (public member function)
   destructor destructs the queue
                 (public member function)
   operator= assigns values to the container adaptor
                 (public member function)

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

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

Modifiers
   push inserts element at the end
                 (public member function)
   emplace constructs element in-place at the end
   (C++11) (public member function)
   pop removes the first element
                 (public member function)
   swap swaps the contents
   (C++11) (public member function)

Member objects
   Container c the underlying container
                 (protected member object)

Non-member functions
   operator==
   operator!=
   operator<
   operator<= lexicographically compares the values in the queue
   operator> (function template)
   operator>=
   operator<=>
   (C++20)
   std::swap(std::queue) specializes the std::swap algorithm
   (C++11) (function template)

Helper classes
   std::uses_allocator<std::queue> specializes the std::uses_allocator type trait
   (C++11) (class template specialization)
  Deduction guides(since C++17)

See also
   deque double-ended queue
         (class template)