field_ initializer_ in_ struct
Constructors in subclasses of 'Struct' and 'Union' can't have field initializers.
Description
#
The analyzer produces this diagnostic when a constructor in a subclass of
either
Struct
or
Union
has one or more field initializers.
For more information about FFI, see C interop using dart:ffi.
Example
#
The following code produces this diagnostic because the class
C
has a
constructor with an initializer for the field
f
:
// @dart = 2.9
import 'dart:ffi';
final class C extends Struct {
@Int32()
int f;
C() : f = 0;
}
Common fixes
#Remove the field initializer:
// @dart = 2.9
import 'dart:ffi';
final class C extends Struct {
@Int32()
int f;
C();
}
Unless stated otherwise, the documentation on this site reflects Dart 3.9.2. Page last updated on 2025-9-4. View source or report an issue.