sdk_version_eq_eq_operator_in_const_context

Using the operator '==' for non-primitive types wasn't supported until version 2.3.2, but this code is required to be able to run on earlier versions.

The analyzer produces this diagnostic when the operator == is used on a non-primitive type inside a constant contextConstant contextA region of code where the const keyword is implied and everything within that region must be a constant. Learn more is found in code that has an SDK constraint whose lower bound is less than 2.3.2. Using this operator in a constant contextConstant contextA region of code where the const keyword is implied and everything within that region must be a constant. Learn more wasn't supported in earlier versions, so this code won't be able to run against earlier versions of the SDK.

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:

class C {}
const C a = null;
const C b = null;
const bool same = a == b;

If you don't need to support older versions of the SDK, then you can increase the SDK constraint to allow the operator 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 the == operator, or change the code so that the expression isn't in a constant contextConstant contextA region of code where the const keyword is implied and everything within that region must be a constant. Learn more:

class C {}
const C a = null;
const C b = null;
bool same = a == b;