Iterator:
  Ctor (copy)	    16
  Ctor (base type)  3
  Dtor		    19
  -		    1
  --		    4

Value type:
  =		    2

Difference type:
  Ctor (default)    2
  Dtor		    2
  =		    1
  >		    3
  --		    2

Total:
  Ctor (default)    2
  Ctor (copy)	    16
  Ctor (base type)  3
  Dtor		    21
  =		    3
  -		    1
  >		    3
  --		    6