cpp/ranges/adjacent transform view/iterator/iterator

Construct an iterator.

@1@ Default constructor. Value-initializes the underlying pointer with, and default-initializes the underlying iterator.

@2@ Conversion from to. Initializes the underlying pointer with, and move constructs the underlying iterator  with.

@3@ This iterator also has a private constructor which is used by ranges and ranges. This constructor is not accessible to users. Initializes with, and move constructs  with.