internal implementation of stl stack and queues

Question

I am using a stl stacks and queues for storing a large collection of items. How is stack in standard template lib implemented internally? Is it in the form of linked list? or is there any maximum size given to it?

Answer 1

vector works internally...


#include <iostream>
#include <vector>

struct Sample
{
    Sample(){}
    Sample(const Sample & obj)
    {
        std::cout<<"Sample copy constructor"<<std::endl;
    }
};
int main()
{
    std::vector<Sample> vecOfInts;

    std::cout<<"Capacity :: "<<vecOfInts.capacity()<<std::endl;
    std::cout<<"Size :: "<<vecOfInts.size()<<std::endl;
    int capcity = vecOfInts.capacity();
    for(int i = 0; i < capcity + 1; i++)
        vecOfInts.push_back(Sample());

    std::cout<<"Capacity :: "<<vecOfInts.capacity()<<std::endl;
        std::cout<<"Size :: "<<vecOfInts.size()<<std::endl;

    for(int i = 0; i < capcity + 1; i++)
            vecOfInts.push_back(Sample());

    std::cout<<"Capacity :: "<<vecOfInts.capacity()<<std::endl;
    std::cout<<"Size :: "<<vecOfInts.size()<<std::endl;

    return 0;
}

Answer 2

Both stacks and queues in C++ standard library are container adaptors. It means that they use specified container as the underlying means to store data. By default both of them use std::deque but you can use e.g. vector with

std::stack<int,std::vector<int>> s;