non_constant_set_element

The values in a const set literal must be constants.

The analyzer produces this diagnostic when a constant set literal contains an element that isn't a compile-time constant.

The following code produces this diagnostic because i isn't a constant:

var i = 0;

var s = const {i};

If the element can be changed to be a constant, then change it:

const i = 0;

var s = const {i};

If the element can't be a constant, then remove the keyword const:

var i = 0;

var s = {i};

Unless stated otherwise, the documentation on this site reflects Dart 3.8.0. Page last updated on 2025-05-08. View source or report an issue.