In some cases the 13.0 compiler incorrectly analyzes the function return type when the function is used to declare a defined constructor or generic interface. I've attached a little example code. BTW, I know how to work around this bug.
Thank you for reporting this issue and the excellent test case. I have escalated it to the developers. The issue number is DPD200237117. I will post any updates I receive to this thread.
Intel Developer Support
A fix has been found for this issue. We are currently planning to include it in the next major release.
This bug was fixed in the recent Composer XE 2013 SP1 release, released in early September ( version 14.0 of the compiler )