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std::stack

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

The std::stack class is a container adaptor that gives the programmer the functionality of a stack - specifically, a LIFO (last-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 stack pushes and pops the element from the back of the underlying container, known as the top of the stack.

Template parameters

T - The type of the stored elements. The behavior is undefined if T is not the same type as Container::value_type.
Container - 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()
  • push_back()
  • pop_back()

The standard containers std::vector (including std::vector<bool>), std::deque and std::list satisfy these requirements. By default, if no container class is specified for a particular stack class instantiation, the standard container std::deque is used.

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 stack
(public member function)
destructs the stack
(public member function)
assigns values to the container adaptor
(public member function)
Element access
accesses the top element
(public member function)
Capacity
checks whether the underlying container is empty
(public member function)
returns the number of elements
(public member function)
Modifiers
inserts element at the top
(public member function)
(C++11)
 constructs element in-place at the top
(public member function)
(C++23)
 inserts a range of elements at the top
(public member function)
removes the top 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

(C++20)
 lexicographically compares the values in the stack
(function template)
(C++11)
 specializes the std::swap algorithm
(function template)

Helper classes

(C++11)
 specializes the std::uses_allocator type trait
(class template specialization)

Deduction guides

(since C++17)

Notes

Feature-test macro Value Std Comment
__cpp_lib_containers_ranges 202202L (C++23) Ranges construction and insertion for containers

Example

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 307 C++98 Container could not be std::vector<bool> allowed

See also

dynamic contiguous array
(class template)
space-efficient dynamic bitset
(class template specialization)
double-ended queue
(class template)
doubly-linked list
(class template)

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