non_positive_array_dimension

Array dimensions must be positive numbers.

The analyzer produces this diagnostic when a dimension given in an Array annotation is less than or equal to zero (0).

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

The following code produces this diagnostic because an array dimension of -8 was provided:

import 'dart:ffi';

final class MyStruct extends Struct {
  @Array(-8)
  external Array<Uint8> a0;
}

Change the dimension to be a positive integer:

import 'dart:ffi';

final class MyStruct extends Struct {
  @Array(8)
  external Array<Uint8> a0;
}

If this is a variable length inline array, change the annotation to Array.variable():

import 'dart:ffi';

final class MyStruct extends Struct {
  @Array.variable()
  external Array<Uint8> a0;
}

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.