C.5 Pragma Discard_Names

A pragma Discard_Names may be used to request a reduction in storage used for the names of certain entities.
Syntax
The form of a pragma Discard_Names is as follows:
```
pragma Discard_Names[([On => ] local_name)];
```
1. A pragma Discard_Names is allowed only immediately within a declarative_part, immediately within a package_specification, or as a configuration pragma.

Legality Rules

The local_name (if present) shall denote a non-derived enumeration first subtype, a tagged first subtype, or an exception. The pragma applies to the type or exception. Without a local_name, the pragma applies to all such entities declared after the pragma, within the same declarative region. Alternatively, the pragma can be used as a configuration pragma. If the pragma applies to a type, then it applies also to all descendants of the type.
Static Semantics
If a local_name is given, then a pragma Discard_Names is a representation pragma.
If the pragma applies to an enumeration type, then the semantics of the Wide_Image and Wide_Value attributes are implementation defined for that type; the semantics of Image and Value are still defined in terms of Wide_Image and Wide_Value. In addition, the semantics of Text_IO.Enumeration_IO are implementation defined. If the pragma applies to a tagged type, then the semantics of the Tags.Expanded_Name function are implementation defined for that type. If the pragma applies to an exception, then the semantics of the Exceptions.Exception_Name function are implementation defined for that exception.
Implementation Advice
If the pragma applies to an entity, then the implementation should reduce the amount of storage used for storing names associated with that entity.