TrivialIterator<T> Concept
  An iterator is generalization of a pointer. An iterator may have limitations regarding how it can move.
  Definition
  Line 109 of System.Base/Concept.cm
  Refinement
  
   
  
  Type Parameters
  
  Constraints
  T is Semiregular
  
  typename T.ValueType
  
  T.ValueType is Semiregular
  
  typename T.ReferenceType
  
  T.ReferenceType operator*()
  
  typename T.PointerType
  
  T.PointerType operator->()