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November 24, 2012
passing struct literals by reference (dmd 2.060, Windows)
struct Foo {
  int a;
}
void modify(ref Foo foo) {
  foo.a++;
}
void main() {
  modify(Foo(1));
}

Why compiler doesn't report error? So as struct literal "Foo()" 
isn't a lvalue, it's impossible to pass it by reference. Isn't it?
Just like string or numeric literals.
November 24, 2012
Re: passing struct literals by reference (dmd 2.060, Windows)
On Saturday, November 24, 2012 10:59:24 Jack Applegame wrote:
> struct Foo {
>    int a;
> }
> void modify(ref Foo foo) {
>    foo.a++;
> }
> void main() {
>    modify(Foo(1));
> }
> 
> Why compiler doesn't report error? So as struct literal "Foo()"
> isn't a lvalue, it's impossible to pass it by reference. Isn't it?
> Just like string or numeric literals.

It should be illegal, but in C++, struct literals are lvalues for some reason, 
and D inherited that stupidity (it's just less noticeable in C++, because of 
how C++ handles const&). We managed to get Walter to change it temporarily, 
but he seems to have changed it back. I thought that I'd reported it, but I 
don't see a bug report for it now. I'll have to go create one.

- Jonathan M Davis
November 24, 2012
Re: passing struct literals by reference (dmd 2.060, Windows)
On Saturday, November 24, 2012 02:11:23 Jonathan M Davis wrote:
> On Saturday, November 24, 2012 10:59:24 Jack Applegame wrote:
> > struct Foo {
> > 
> >    int a;
> > 
> > }
> > void modify(ref Foo foo) {
> > 
> >    foo.a++;
> > 
> > }
> > void main() {
> > 
> >    modify(Foo(1));
> > 
> > }
> > 
> > Why compiler doesn't report error? So as struct literal "Foo()"
> > isn't a lvalue, it's impossible to pass it by reference. Isn't it?
> > Just like string or numeric literals.
> 
> It should be illegal, but in C++, struct literals are lvalues for some
> reason, and D inherited that stupidity (it's just less noticeable in C++,
> because of how C++ handles const&). We managed to get Walter to change it
> temporarily, but he seems to have changed it back. I thought that I'd
> reported it, but I don't see a bug report for it now. I'll have to go
> create one.

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

- Jonathan M Davis
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