The supertype of all annotation classes.

### Annotation classes

An annotation class must satisfy `Annotation`, `OptionalAnnotation`, or `SequencedAnnotation` and must be annotated `final annotation`. For example:

    "An annotation class."
    final annotation class Example(shared String description)
          satisfies Annotation {}

Annotation classes which satisfy `Annotation` directly may be applied to any program element that supports annotations (see `Annotated`). In practice, annotation classes often satisfy `OptionalAnnotation` or `SequencedAnnotation` in order to prevent annotations being applied to inappropriate program elements.

Each initializer parameter of an annotation class must have one of the following types:

- `Integer`, `Float`, `Character`, or `String`,
- an enumerated type whose cases are all anonymous classes, such as `Boolean`,
- a subtype of `Declaration`
- an annotation class,
- `{T*}` or `[T*]` where `T` is a legal annotation parameter type, or
- any tuple type whose element types are legal annotation parameter types.

An initializer parameter of an annotation class may be variadic or defaulted.

### Annotation constructors

An annotation constructor is simply a top level function, annotated with `annotation` whose return type is an annotation class type. For example:

    "An annotation constructor."
    annotation Example example(String description="")
        => Example(description);

Each parameter of an annotation constructor must have one of the following types:

- `Integer`, `Float`, `Character`, or `String`,
- an enumerated type whose cases are all anonymous classes, such as `Boolean`,
- a subtype of `Declaration`,
- an annotation type,
- `{T*}` or `[T*]` where `T` is a legal annotation constructor parameter type, or
- any tuple type whose element types are legal annotation constructor parameter types.

A parameter of an annotation constructor may be variadic or defaulted.

The constructor must simply instantiate and return the annotation class, and there are strict rules about the arguments to the instantiation.

A given annotation class can have multiple annotation constructors.

See also `OptionalAnnotation`, `SequencedAnnotation`, `annotations()`, `optionalAnnotation()`, `sequencedAnnotations()`

no type hierarchy

no supertypes hierarchy

- `Annotation` of
  - `ConstrainedAnnotation`
    - `OptionalAnnotation`
      - `AbstractAnnotation`
      - `ActualAnnotation`
      - `AliasesAnnotation`
      - `AnnotationAnnotation`
      - `AuthorsAnnotation`
      - `DefaultAnnotation`
      - `DeprecationAnnotation`
      - `DocAnnotation`
      - `FinalAnnotation`
      - `FormalAnnotation`
      - `LateAnnotation`
      - `LicenseAnnotation`
      - `NativeAnnotation`
      - `OptionalImportAnnotation`
      - `SealedAnnotation`
      - `SerializableAnnotation`
      - `SharedAnnotation`
      - `SuppressWarningsAnnotation`
      - `TagsAnnotation`
      - `VariableAnnotation`
    - `SequencedAnnotation`
      - `SeeAnnotation`
      - `ThrownExceptionAnnotation`

Inherited Attributes
Attributes inherited from: `Object` `hash`, `string`

Inherited Methods
Methods inherited from: `Object` `equals()`