NAME¶

std::stack - std::stack

Synopsis¶

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 program is ill-formed if T is not
the same type as Container::value_type.
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(), e.g., std::vector::back(),
Container - * push_back(), e.g., std::deque::push_back(),
* pop_back(), e.g., std::list::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 objects¶

Member name Definition
Container c the underlying container
(protected member object)

Member functions¶

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

Element access¶

top accesses the top element
(public member function)

Capacity¶

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

Modifiers¶

push inserts element at the top
(public member function)
push_range inserts a range of elements at the top
(C++23) (public member function)
emplace constructs element in-place at the top
(C++11) (public member function)
pop removes the top element
(public member function)
swap swaps the contents
(C++11) (public member function)

Non-member functions¶

operator==
operator!=
operator<
operator<= lexicographically compares the values of two stacks
operator> (function template)
operator>=
operator<=>
(C++20)
std::swap(std::stack) specializes the std::swap algorithm
(C++11) (function template)

Helper classes¶

std::uses_allocator<std::stack> specializes the std::uses_allocator type trait
(C++11) (class template specialization)
std::formatter<std::stack> formatting support for std::stack
(C++23) (class template specialization)

Deduction guides (since C++17)

Notes¶

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

Example¶

This section is incomplete
Reason: no 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 allowed
std::vector<bool>
LWG 2566 C++98 Missing the requirement for ill-formed if T is not the same type
Container::value_type as Container::value_type

See also¶

vector dynamic contiguous array
(class template)
vector<bool> space-efficient dynamic bitset
(class template specialization)
deque double-ended queue
(class template)
list doubly-linked list
(class template)

Category:¶

* Todo no example