3rdParty/boost/1.78.0/libs/iterator/doc/ForwardTraversal.rst
.. Copyright David Abrahams 2006. Distributed under the Boost .. Software License, Version 1.0. (See accompanying .. file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Forward Traversal Concept .........................
A class or built-in type X models the Forward Traversal
concept if, in addition to X meeting the requirements of Default
Constructible and Single Pass Iterator, the following expressions are
valid and respect the stated semantics.
+--------------------------------------------------------------------------------------------------------+
|Forward Traversal Iterator Requirements (in addition to Default Constructible and Single Pass Iterator) |
+---------------------------------------+-----------------------------------+----------------------------+
|Expression |Return Type |Assertion/Note |
+=======================================+===================================+============================+
|X u; |X& |note: u may have a |
| | |singular value. |
+---------------------------------------+-----------------------------------+----------------------------+
|++r |X& |r == s and r is |
| | |dereferenceable implies |
| | |++r == ++s. |
+---------------------------------------+-----------------------------------+----------------------------+
|iterator_traits<X>::difference_type|A signed integral type representing| |
| |the distance between iterators | |
| | | |
+---------------------------------------+-----------------------------------+----------------------------+
|iterator_traversal<X>::type |Convertible to | |
| |forward_traversal_tag | |
+---------------------------------------+-----------------------------------+----------------------------+