non_ const_ argument_ for_ const_ parameter
Argument '{0}' must be a constant.
Description
#
The analyzer produces this diagnostic when a parameter is
annotated with the
mustBeConst
annotation and
the corresponding argument is not a constant expression.
Example
#
The following code produces this diagnostic on the invocation of
the function
f
because the value of the argument passed to the
function
g
isn't a constant:
import 'package:meta/meta.dart' show mustBeConst;
int f(int value) => g(value);
int g(@mustBeConst int value) => value + 1;
Common fixes
#If a suitable constant is available to use, then replace the argument with a constant:
import 'package:meta/meta.dart' show mustBeConst;
const v = 3;
int f() => g(v);
int g(@mustBeConst int value) => value + 1;
Unless stated otherwise, the documentation on this site reflects Dart 3.9.2. Page last updated on 2025-9-1. View source or report an issue.