field_in_struct_with_initializer

Fields in subclasses of 'Struct' and 'Union' can't have initializers.

The analyzer produces this diagnostic when a field in a subclass of Struct has an initializer.

For more information about FFI, see C interop using dart:ffi.

The following code produces this diagnostic because the field p has an initializer:

// @dart = 2.9
import 'dart:ffi';

final class C extends Struct {
  Pointer p = nullptr;
}

Remove the initializer:

// @dart = 2.9
import 'dart:ffi';

final class C extends Struct {
  Pointer p;
}

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.