extra_annotation_on_struct_field
Fields in a struct class must have exactly one annotation indicating the native type.
Description
#The analyzer produces this diagnostic when a field in a subclass of Struct
has more than one annotation describing the native type of the field.
For more information about FFI, see C interop using dart:ffi.
Example
#The following code produces this diagnostic because the field x
has two annotations describing the native type of the field:
import 'dart:ffi';
final class C extends Struct {
@Int32()
@Int16()
external int x;
}
Common fixes
#Remove all but one of the annotations:
import 'dart:ffi';
final class C extends Struct {
@Int32()
external int x;
}
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.