title: Find if one map is subset of another
body: <p>I have two STL maps <code>std::map&lt;int, int&gt; foo = {{1, 0}, {2, 0}, {3, 0}, {4, 0}, {5, 0}, {6, 0}};</code> and <code>std::map&lt;int, int&gt; bar = {{2, 0}, {4, 0}, {5, 0}};</code></p>
  
  <p>I want to find if bar is a subset of foo.</p>
  
  <p>Since the elements are sorted in map, I would think
  to find the first element from bar in foo, and then find consecutive elements 
  from bar in foo from that location.</p>
  
  <p>The problem here is I'm not able to figure out a way to do that with STL maps in cpp.
  Can I reduce the search range in map for every find from a location in map to the end of the map?</p>
  
  <p>I hope I explained the problem.</p>