C++ std::stack

std::stack

template <class T, class Container = deque<T> > class stack;

LIFO stack

Stacks are a type of container adaptor, specifically designed to operate in a LIFO context (last-in first-out), where elements are inserted and extracted only from one end of the container.

stacks are implemented as containers adaptors, which are classes that use an encapsulated object of a specific container class as its underlying container, providing a specific set of member functions to access its elements. Elements are pushed/popped from the "back" of the specific container, which is known as the top of the stack.

The underlying container may be any of the standard container class templates or some other specifically designed container class. The container shall support the following operations:

• empty
• size
• back
• push_back
• pop_back

The standard container classes vector, deque and list fulfill these requirements. By default, if no container class is specified for a particular stack class instantiation, the standard container deque is used.

Template parameters

• T Type of the elements. Aliased as member type stack::value_type.
• Container Type of the internal underlying container object where the elements are stored. Its value_type shall be T. Aliased as member type stack::container_type.

member type	definition	notes
value_type	The first template parameter (T)	Type of the elements
container_type	The second template parameter (Container)	Type of the underlying container
size_type	an unsigned integral type	usually the same as size_t

Member functions

• (constructor) Construct stack (public member function )
• empty Test whether container is empty (public member function )
• size Return size (public member function )
• top Access next element (public member function )
• push Insert element (public member function )
• emplace Construct and insert element (public member function )
• pop Remove top element (public member function )
• swap Swap contents (public member function )

Non-member function overloads

• relational operators Relational operators for stack (function )
• swap (stack) Exchange contents of stacks (public member function )

Non-member class specializations

• uses__allocator Uses allocator for stack (class template )

Code Example

#include <iostream>
#include <stack>
#include <vector>
#include <deque>

using namespace std;

int main(int argc, char **argv)
{
    deque<int> mydeque(3,10);
    vector<int> myvector(2,20);

    stack<int> first;
    stack<int> second(mydeque);

    stack<int, vector<int> > third;
    stack<int, vector<int> > fourth(myvector);

    /** other function please to see the deque container */
    return 0;
}

Reference

cplusplus

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