meta 1.1.2

  • Installing
  • Versions
  • 98


  • Rollback SDK constraint update for 2.0.0. No longer needed.


  • Update SDK constraint to be 2.0.0 dev friendly.


  • Introduce @alwaysThrows to declare that a function always throws (SDK issue 17999). This is first available in Dart SDK 1.25.0-dev.1.0.

      import 'package:meta/meta.dart';
      // Without knowing that [failBigTime] always throws, it looks like this
      // function might return without returning a bool.
      bool fn(expected, actual) {
        if (expected != actual)
          failBigTime(expected, actual);
          return True;
      void failBigTime(expected, actual) {
        throw new StateError('Expected $expected, but was $actual.');


  • Introduce @virtual to allow field overrides in strong mode (SDK issue 27384).

      import 'package:meta/meta.dart' show virtual;
      class Base {
        @virtual int x;
      class Derived extends Base {
        int x;
        // Expose the hidden storage slot:
        int get superX => super.x;
        set superX(int v) { super.x = v; }


  • Introduce @checked to override a method and tighten a parameter type (SDK issue 25578).

      import 'package:meta/meta.dart' show checked;
      class View {
        addChild(View v) {}
      class MyView extends View {
        // this override is legal, it will check at runtime if we actually
        // got a MyView.
        addChild(@checked MyView v) {}
      main() {
        dynamic mv = new MyView();
        mv.addChild(new View()); // runtime error


  • Introduce @visibleForTesting annotation for declarations that may be referenced only in the library or in a test.


  • Updated @factory to allow statics and methods returning null.


  • First stable API release.


  • Updated @protected to include implemented interfaces (linter#252).


  • Fixed markdown in dartdocs.


  • Introduce @optionalTypeArgs annotation for classes whose type arguments are to be treated as optional.


  • Added new Required constructor with a means to specify a reason to explain why a parameter is required.


  • Introduce @factory annotation for methods that must either be abstract or must return a newly allocated object.
  • Introduce @literal annotation that indicates that any invocation of a constructor must use the keyword const unless one or more of the arguments to the constructor is not a compile-time constant.


  • Introduce @protected annotation for members that must only be called from instance members of subclasses.
  • Introduce @required annotation for optional parameters that should be treated as required.
  • Introduce @mustCallSuper annotation for methods that must be invoked by all overriding methods.

1. Depend on it

Add this to your package's pubspec.yaml file:

  meta: "^1.1.2"

2. Install it

You can install packages from the command line:

with pub:

$ pub get

with Flutter:

$ flutter packages get

Alternatively, your editor might support pub get or packages get. Check the docs for your editor to learn more.

3. Import it

Now in your Dart code, you can use:

import 'package:meta/meta.dart';
Version Uploaded Documentation Archive
1.1.2 Sep 28, 2017 Go to the documentation of meta 1.1.2 Download meta 1.1.2 archive
1.1.1 Jul 19, 2017 Go to the documentation of meta 1.1.1 Download meta 1.1.1 archive
1.1.0 Jul 10, 2017 Go to the documentation of meta 1.1.0 Download meta 1.1.0 archive
1.0.5 Mar 31, 2017 Go to the documentation of meta 1.0.5 Download meta 1.0.5 archive
1.0.4 Sep 20, 2016 Go to the documentation of meta 1.0.4 Download meta 1.0.4 archive
1.0.3 Sep 14, 2016 Go to the documentation of meta 1.0.3 Download meta 1.0.3 archive
1.0.2 Aug 15, 2016 Go to the documentation of meta 1.0.2 Download meta 1.0.2 archive
1.0.1 Jun 27, 2016 Go to the documentation of meta 1.0.1 Download meta 1.0.1 archive
0.12.1 Apr 18, 2016 Go to the documentation of meta 0.12.1 Download meta 0.12.1 archive
0.12.0 Apr 12, 2016 Go to the documentation of meta 0.12.0 Download meta 0.12.0 archive

All 83 versions...


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We analyzed this package, and provided a score, details, and suggestions below.

  • completed on Dec 6, 2017
  • Dart: 2.0.0-dev.8.0
  • pana: 0.7.3+1


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Overall score:
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Detected platforms: Flutter, server, web

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