Proposal: Support a named type for enumerators, and perhaps other intrinsic types as well.
Fortran2003 defines the ENUMERATOR type, similar to C enum. Unlike C, a specific enumerator cannot be a defined type. A named type attribute helps avoid errors by ensuring that a given enumerator is used in the correct context, and can be used to distinguish specific procedures in a generic interface.
A [somewhat ugly] work-around is to encapsulate an integer enum inside of a derived type. It is not a clean work-around because a derived type cannot be passed by value.
A possible syntax is to follow the derived-type syntax:
ENUM, BIND(C) :: COLOR ENUMERATOR :: RED = 4, BLUE = 9 ENUMERATOR YELLOW END ENUM TYPE(COLOR) :: MYCOLOR = BLUE
Unlike a true derived type, this type is scalar and has no member-selector syntax.
A different syntax is required to support other intrinsic types. It is not unusual for an integer to be used as a unique object ID, so confering a type name onto a scalar integer is reasonable.
Maybe define an ALIAS attribute? Maybe there was also a proposal for this sort of alias that never made the standards? In this case, the TYPE stantement is a single line rather than a multi-line construct. For example:
TYPE, ALIAS(INTEGER(8)) :: OBJECT_ID