VBC09328 — Invalid Implements directive

Severity: Error · Family: VBC (static semantics / abstract syntax tree) · Source metadata: VBCompileErrorInfo

An Implements directive names a class that cannot be an interface class of this module, or the directives of the module do not go together.

MS-VBAL §5.2.4.2 Implements Directive gives the rules.

This code is raised by ImplementsSemantics. The verbose detail says which rule.

How it is raised

Situation	Example, in the class module `Disc`	Resolution
The interface class is the class of the module itself.	`Implements Disc`	A class cannot implement itself.
A class is the interface class of more than one directive of the module.	`Implements IShape` twice	Name it once.
The module is extensible (`VB_Extensible = True`).	Any `Implements` directive	Remove the directive: an extensible module cannot implement an interface.
The class has a public variable or method with an underscore in its name.	`Implements IBad`, where `IBad` has `Public Sub Do_It()`	Rename the member, or make it `Private`. The underscore is where the interface's name ends in the name of an implementation.
The implemented interface name prefix of one interface begins the prefix of another.	`Implements IA` and `Implements IA_B`: the prefix `IA_` begins `IA_B_`	Rename an interface, so that `IA_B_Member` does not read as `IA_`'s `B_Member`.

A name that is no class at all is not reported with this code: it is VBC09311 (user-defined type not defined).