[Issue 13336] New: auto ref return deduced to be ref despite return value coercion

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=13336

          Issue ID: 13336
           Summary: auto ref return deduced to be ref despite return value
                    coercion
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: normal
          Priority: P1
         Component: DMD
          Assignee: nobody at puremagic.com
          Reporter: peter.alexander.au at gmail.com

------------------------
int sx;
double sy;

auto ref foo()
{
  if (1)
    return sx;
  return sy;
}
------------------------

foo is determined to return a 'ref double', even though sx is not a double. It
is cast to a double and a ref to the temporary is returned.

Expected behaviour: When common-type coercions are involved, auto ref should
deduce to be non-ref otherwise the code becomes unsafe and surprising.

The spec doesn't say anything about this, it just says "The lexically first
ReturnStatement determines the ref-ness of a function".

--