can't use subtraction to initialize int in const constructor

[DartBot]

This issue was originally filed by [email protected]

---

This works:

class DigitSet {
  final int bits;
  const DigitSet.single(int digit) : bits = 1 << digit;
}

This doesn't:

class DigitSet {
  final int bits;
  const DigitSet.single(int digit) : bits = 1 << (digit - 1);
}

The Dart editor reports an error for the const constructor: "An expression of type int was expected".

If you remove "const" it also works.

The problem seems to be that the subtraction operator is declared to return a "num" and for some reason, Dart doesn't automatically downcast it to "int" when the constructor is marked "const".

[lrhn]

Added Area-Analyzer, Accepted labels.

[bwilkerson]

Added this to the M6 milestone.
Removed Priority-Unassigned label.
Added Priority-Medium label.

[bwilkerson]

Set owner to @bwilkerson.
Added Started label.

[bwilkerson]

https://codereview.chromium.org/23382010/ (bleeding edge revision 26539)

---

Added Fixed label.