kotlin未型变的类经过android studio make project后会变成形变的类

[longqingzhao]

我写了一个kt类如下:
class ViewModelProviderFactory @Inject
constructor(private val creators: Map<Class, Provider>) :
ViewModelProvider.Factory {

override fun <T : ViewModel> create(modelClass: Class<T>) =
    (creators[modelClass]
        ?: creators.filterKeys { it.isAssignableFrom(modelClass) }.values.first()).get() as T

}
然后我点击android studio->build->make project后生成的java类如下:

public final class ViewModelProviderFactory_Factory implements Factory<ViewModelProviderFactory> {
  private final Provider<Map<Class<? extends ViewModel>, ? extends Provider<ViewModel>>>
      creatorsProvider;

  public ViewModelProviderFactory_Factory(
      Provider<Map<Class<? extends ViewModel>, ? extends Provider<ViewModel>>> creatorsProvider) {
    this.creatorsProvider = creatorsProvider;
  }

  @Override
  public ViewModelProviderFactory get() {
    return new ViewModelProviderFactory(creatorsProvider.get());
  }

  public static ViewModelProviderFactory_Factory create(
      Provider<Map<Class<? extends ViewModel>, ? extends Provider<ViewModel>>> creatorsProvider) {
    return new ViewModelProviderFactory_Factory(creatorsProvider);
  }

  public static ViewModelProviderFactory newInstance(
      Map<Class<? extends ViewModel>, ? extends Provider<ViewModel>> creators) {
    return new ViewModelProviderFactory(creators);
  }
}

以上出现了一个问题:我并没有让Provider进行任何型变操作,生成的java类意外地出现了? extexds.我想这是一个bug!因为当我试着用java写这段代码时并没生成? extends而且代码运行正常.所以这是一个bug!

[tbroyer]

You need to use @JvmSuppressWildcard; see #900 (comment)

[longqingzhao]

Thank you very much!