deprecated_ mixin
Mixing in '{0}' is deprecated.
Description
#
The analyzer produces this diagnostic when a mixin class annotated with
@Deprecated.mixin
is used in the
with
clause of a class or enum
declaration. This annotation indicates that the ability for classes
to mixin the annotated mixin class is deprecated, and will soon be
removed, perhaps by removing the
mixin
class modifier.
Example
#If the library p
defines a class annotated with @Deprecated.mixin
:
@Deprecated.mixin()
mixin class C {}
Then, the following code, when in a library other than
p
, produces this
diagnostic:
import 'package:p/p.dart';
class D with C {}
Common fixes
#
Follow any directions found in the
Deprecation.mixin
annotation, or
just remove the mixin class name from the
with
clause.
class D {}
Unless stated otherwise, the documentation on this site reflects Dart 3.9.2. Page last updated on 2025-9-5. View source or report an issue.