stack

A stack is an adapter that can use any container that supports push_back() and pop_back() as a first-in, last-out data structure. This section provides an overview of stack .

Iterator Type

Because adapters do not support iteration, a stack has no associated iterator.

Implementation

A stack is implemented as a class comprised of inline functions converting push() and pop() messages into push_back() and pop_back() messages. Although a stack can use any kind of sequential container as its underlying data structure, a deque or vector yields the best performance.

Common Uses

A stack is useful for implementing strictly first-in, last-out data structures when direct indexed access to the items is not performed.

Interface

In addition to the common set of collection operations, stacks offer the following behaviors.

push: void push( const T&value ); Pushes a copy of value onto the stack .
pop: void pop(); Erases the top value from the stack . Note that pop() does not return a value.
top: T& top(); Returns a reference to the top value.

The following example of a stack uses a deque as its underlying data structure.

Example <ospace/osstd/examples/stack1.cpp>


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

void
main()
  {
  stack< int, deque< int > > s;
  s.push( 42 );
  s.push( 101 );
  s.push( 69 );
  while ( !s.empty() )
    {
    cout << s.top() << "\n";
    s.pop();
    }
  }

69
101
42

Following is the same program, this time using a list as the underlying data structure.

Example <ospace/osstd/examples/stack2.cpp>


  #include <iostream>
#include <list>
#include <stack>

void
main()
  {
  stack< int, list< int > > s;
  s.push( 42 );
  s.push( 101 );
  s.push( 69 );
  while ( !s.empty() )
    {
    cout << s.top() << "\n";
    s.pop();
    }
  }

69
101
42