title: What is vector<int,int> Is it even valid?
body: <p>I have been working with <code>vector &lt; pair &lt; int,int&gt;&gt;</code> but I didnt know that something like <code>vector&lt; int,int&gt;</code> also exists and I can declare it,
  but dont know how to use it.</p>
  
  <p>Is <code>vector &lt; int,int&gt;</code> a valid container,if yes whats the difference between that 
  and <code>vector &lt; pair &lt; int,int&gt;&gt;</code> ?</p>
  
  <p>if no, why am I able to declare it??</p>