I just tried to build the Juno library with DMD 2.037, and got a bunch or errors like:

juno\com\core.d(295): Error: function juno.com.core.GUID.opEquals type signature should be const bool(ref const(GUID)) not bool(GUID other)

Which can be replicated with:
////////////////////////////////
struct Foo
{
	bool opEquals(Foo f) const
	{
		return true;
	}
}

void Bar()
{
	Foo f;
}
////////////////////////////////

It built ok with DMD2 a few months ago. Is this an intentional change?

Also, while looking at the problem i noticed that code like:

////////////////////////////////
struct Foo
{
	~this()
	{

	}
}

void Bar()
{
	const Foo f;
}
////////////////////////////////

Produces the error:

Error: destructor Foo.~this () is not callable using argument types ()

which seems a bit wrong?

Thanks,
Richard Webb

On Thu, 10 Dec 2009 19:23:43 -0500, Richard Webb <webby@beardmouse.org.uk> wrote:

> I just tried to build the Juno library with DMD 2.037, and got a bunch or errors like:
>
> juno\com\core.d(295): Error: function juno.com.core.GUID.opEquals type signature should be const bool(ref const(GUID)) not bool(GUID other)
>
> Which can be replicated with:
> ////////////////////////////////
> struct Foo
> {
> 	bool opEquals(Foo f) const
> 	{
> 		return true;
> 	}
> }
>
> void Bar()
> {
> 	Foo f;
> }
> ////////////////////////////////
>
> It built ok with DMD2 a few months ago. Is this an intentional change?

It's due to this change: http://www.dsource.org/projects/dmd/changeset/260

The issue being fixed was this:

http://d.puremagic.com/issues/show_bug.cgi?id=3433

I think it should be a bug, because your opEquals does not violate const, since you are making a copy of a Foo, and Foo contains no references.  Please file a bug and reference 3433 and changeset 260.  I think it should be allowed to have a signature like this:

bool opEquals(T other) const

inside T as long as T can be implicitly cast from const to mutable.

>
> Also, while looking at the problem i noticed that code like:
>
> ////////////////////////////////
> struct Foo
> {
> 	~this()
> 	{
> 		
> 	}
> }
>
> void Bar()
> {
> 	const Foo f;
> }
> ////////////////////////////////
>
> Produces the error:
>
> Error: destructor Foo.~this () is not callable using argument types ()
>
> which seems a bit wrong?
>

Yeah, that's weird.  Probably something to do with const.  Probably should file another bug :)

-Steve

On Fri, 11 Dec 2009 07:13:35 -0500, Steven Schveighoffer <schveiguy@yahoo.com> wrote:


> I think it should be a bug

Clarifying, I meant it is a bug in the compiler *not* in Juno :)

-Steve

Opened as 3606 and 3607.

Thanks,
Richard Webb