how to print out all elements in a std::stack or std::queue conveniently

Question

If I do not to want to create a new container in order to do so?

Answer 1

Try this:

template
struct myStack : std::stack {
    typedef std::stack Stack;
    using Stack::stack;
    using Stack::c;                   
};

int main() 
{
    myStack> s;
    s.push(1);
    s.push(2);

    std::deque::iterator it = s.c.begin();
    while (it != s.c.end())
        std::cout << ' ' << *it++;
}

Here we expose underlying container of std::stack as member c.