const_ spread_ expected_ list_ or_ set
A list or a set is expected in this spread.
Description
#The analyzer produces this diagnostic when the expression of a spread operator in a constant list or set evaluates to something other than a list or a set.
Example
#
The following code produces this diagnostic because the value of
list1
is
null
, which is neither a list nor a set:
const dynamic list1 = 42;
const List<int> list2 = [...list1];
Common fixes
#Change the expression to something that evaluates to either a constant list or a constant set:
const dynamic list1 = [42];
const List<int> list2 = [...list1];
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.