Many thanks @jhale!
Your efforts with bisecting lead to the right place.
This issue is because of a strange clang interpretation of C++ language.
The referenced commits were C++11 refactoring. The Visual Studio Error C2797 was caused by a VS regression which was solved in later VS 2013.
But even the
d0a0ef2 code, which is valid for GCC and VS 2015, does not work with Clang.
So I challenged to set up my FreeBSD VM to debug this and I found a solution.
I created issue
#1568 to document this.
The fix will be pushed later today.
I assume, that this will be one of the last commits before I tag finally 2.2.0 official release.
So you can fix this with an update soon.
investing less than half an hour into Search function can save hours or days of waiting for a solution