\brief This class represents a pair of period_type and the integer values that describes its amount. For example 3 days or 4 years. Usually obtained

case insensitive version of is_equal ! Case insensitive comparison predicate. Comparison is done using specified locales.

\brief This class holds a type that represents certain period of time like year, hour, second and so on. It can be created from either marks::period_

Various possible styles of options. There are "long" options, which start with "--" and "short", which start with either "-" or "/".

values defined by the operating system

is_classified functor

is_equal functor ! Standard STL equal_to only handle comparison between arguments of the same type. This is a less restrictive

The permissions class represents permissions to be set to shared memory or files, that can be constructed form usual permission representations: a SEC