generic_method_type_instantiation_on_dynamic

A method tear-off on a receiver whose type is 'dynamic' can't have type arguments.

The analyzer produces this diagnostic when an instance method is being torn off from a receiver whose type is dynamic, and the tear-off includes type arguments. Because the analyzer can't know how many type parameters the method has, or whether it has any type parameters, there's no way it can validate that the type arguments are correct. As a result, the type arguments aren't allowed.

The following code produces this diagnostic because the type of p is dynamic and the tear-off of m has type arguments:

void f(dynamic list) {
  list.fold<int>;
}

If you can use a more specific type than dynamic, then change the type of the receiver:

void f(List<Object> list) {
  list.fold<int>;
}

If you can't use a more specific type, then remove the type arguments:

void f(dynamic list) {
  list.cast;
}

Unless stated otherwise, the documentation on this site reflects Dart 3.7.3. Page last updated on 2025-05-08. View source or report an issue.