Directives are special identifiers that can be used to give the compiler extra information about a declaration/definition. The compiler recognizes directives only at specific points in a declaration/definition, and this recognition is not affected by, and does not affect, any meaning the directive's identifiers may have outside of these specific points. So for example the forward directive is recognized even if the identifier forward has been declared to have some other meaning, and the use of the forward directive does not affect any meaning that forward has been declared to have.
The supported directives are listed below: