WTF did happen with struct constructor and ref in 2.061 ?

[Jonathan M Davis]

On Friday, January 04, 2013 00:20:58 deadalnix wrote:
> I find myself with massive breakage in my codebase. I have a lot
> of code doing stuff like foo(Bar(args)) where foo expect a ref
> parameter. This used to work just fine, but now it do not.
> 
> This seems to me particularly dubious as the compiler introduce a
> temporary to call the constructor on. Bar(args) HAVE an address.
> 
> Looking at the change log, I can't find anything relevant to the
> subject. What the fuck did happen and why ?

http://d.puremagic.com/issues/show_bug.cgi?id=9069

It makes _no_ sense for struct literals to be treated as lvalues. They're 
temporaries, not variables. This has been discussed a number of times before 
and was finally fixed with 2.061. Previously, you got nonsensical behavior like

struct S
{
 int i;
}

S foo(ref S s)
{
 return s;
}

S bar(int i)
{
 return S(i);
}

void main()
{
 S s = S(2);
 foo(s); //compiles as it should
 foo(S(5)); //compiles when it shouldn't
 foo(bar(5)); //fails to compile as it should
}

There should be no difference between a struct literal and a struct returned by 
value from a function. Code which depended on struct literals being lvalues was
depending on buggy behavior.

- Jonathan M Davis