On Thursday, 3 January 2013 at 23:40:39 UTC, Jonathan M Davis
wrote:
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.
This has been discussed, but I'm pretty sure nothing was really
conclusive (especially when I read about auto ref).
And even if it was, how come that this isn't advertised with some
big red sign ? If a person that read the newsgroup like me didn't
see that coming, what about any regular D user ?
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.
But the struct storage is passed to the constructor ! It has an
actual storage !
