The use of an as expression in a constant expression wasn't supported until version 2.3.2, but this code is required to be able to run on earlier versionsDRT-W1608
The analyzer produces this diagnostic when an as
expression inside a
constant context is found in code that has an SDK constraint whose
lower bound is less than 2.3.2. Using an as
expression in a
constant context wasn't supported in earlier versions, so this code
won't be able to run against earlier versions of the SDK.
Example
Here's an example of a pubspec that defines an SDK constraint with a lower bound of less than 2.3.2:
environment:
sdk: '>=2.1.0 <2.4.0'
In the package that has that pubspec, code like the following produces this diagnostic:
const num n = 3;
const int i = n as int;
Common fixes
If you don't need to support older versions of the SDK, then you can increase the SDK constraint to allow the expression to be used:
environment:
sdk: '>=2.3.2 <2.4.0'
If you need to support older versions of the SDK, then either rewrite the
code to not use an as
expression, or change the code so that the as
expression isn't in a constant context:
num x = 3;
int y = x as int;