31 Input/output library [input.output]

Path iterators iterate over the elements of the pathname in the generic format.

A path​::​iterator is a constant iterator meeting all the requirements of a bidirectional iterator except that, for dereferenceable iterators a and b of type path​::​iterator with a == b, there is no requirement that *a and *b are bound to the same object.

Its value_type is path.

Calling any non-const member function of a path object invalidates all iterators referring to elements of that object.

For the elements of the pathname in the generic format, the forward traversal order is as follows:

• (4.1)
  The root-name element, if present.
• (4.2)
  The root-directory element, if present.

  [Note 1: 

  The generic format is required to ensure lexicographical comparison works correctly.

  — end note]
• (4.3)
  Each successive filename element, if present.
• (4.4)
  An empty element, if a trailing non-root directory-separator is present.

The backward traversal order is the reverse of forward traversal.