title: set::key_comp vs set::value_comp in C++?
body: <p>What is the difference between <strong>set::key_comp</strong> vs <strong>set::value_comp</strong> in <strong>C++</strong>? Going to cplusplus.com page there is no significant difference.
  Furthermore on set::key_comp &amp; related set::value_comp pages
  last sentence is "(...) key_comp and its sibling member function value_comp are equivalent."</p>
  
  <p>Examples are almost the same:</p>
  
  <p><a href="http://www.cplusplus.com/reference/set/set/key_comp/" rel="noreferrer">http://www.cplusplus.com/reference/set/set/key_comp/</a></p>
  
  <p><a href="http://www.cplusplus.com/reference/set/set/value_comp/" rel="noreferrer">http://www.cplusplus.com/reference/set/set/value_comp/</a></p>