Queue constructor

  #include <queue>
  queue();
  queue( const Container& con );

Queues have a default constructor as well as a copy constructor that will create a new queue out of the container con.

For example, the following code creates a queue of strings, populates it with input from the user, and then displays it back to the user:

  queue<string> waiting_line;
  while( waiting_line.size() < 5 ) {
    cout << "Welcome to the line, please enter your name: ";
    string s;
    getline( cin, s );
    waiting_line.push(s);
  }

  while( !waiting_line.empty() ) {
    cout << "Now serving: " << waiting_line.front() << endl;
    waiting_line.pop();
  }

When run, the above code might produce this output:

  Welcome to the line, please enter your name: Nate
  Welcome to the line, please enter your name: lizzy 
  Welcome to the line, please enter your name: Robert B. Parker
  Welcome to the line, please enter your name: ralph
  Welcome to the line, please enter your name: Matthew
  Now serving: Nate
  Now serving: lizzy
  Now serving: Robert B. Parker
  Now serving: ralph
  Now serving: Matthew