title: No standard way to compare smart pointer with regular pointer?
body: <p>Why doesn't the C++ standard include comparison operators to compare smart pointers (unique_ptr, shared_ptr, ...) with regular pointers (T*)?</p>
  
  <p>Tom</p>
  
  <p><strong>update</strong>
  I am not looking to find out how it can be done. The question is why is it not defined as part of the C++ standard? For unique_ptr and shared_ptr such definitions would be trivial.</p>
  
  <p>A use case for this is the following:
  Class A has a map with unique_ptr keys. unique_ptr is used for memory management.
  When a user of class A passed a regular pointer, a lookup is performed inside this map. Unfortunately, the standard doesn't define the comparision operators.</p>