invalid_ deprecated_ implement_ annotation
The annotation '@Deprecated.implement' can only be applied to implementable classes.
Description
#
The analyzer produces this diagnostic when anything other than an
implementable class or mixin is annotated with
Deprecated.implement. An implementable
class or mixin is one not declared with the
base
,
final
, or
sealed
keywords.
Example
#The following code produces this diagnostic because the annotation is on a sealed class:
@Deprecated.implement()
sealed class C {}
Common fixes
#Remove the annotation:
sealed class C {}
Unless stated otherwise, the documentation on this site reflects Dart 3.9.2. Page last updated on 2025-9-4. View source or report an issue.