dmd 2.065.0

[Steven Schveighoffer]

On Tue, 25 Feb 2014 15:12:41 -0500, Jacob Carlborg <doob at me.com> wrote:

>
> The thing is that the compiler complains about a deceleration looking  
> like this:
>
> struct TagIndex
> {
>      uint tag, index;
> }

If the compiler generates opEquals and opCmp, then it's guaranteed  
opEquals(x, y) is equivalent to opCmp(x, y) == 0.

The compiler should NOT complain about this, which I should have more  
clearly stated (I thought I had).

> Neither opEquals or opCmp is overloaded. A simple test case will also  
> show that the compiler doesn't not complain about a missing opCmp. I  
> have not been able to create a reduced test case for this.

I realized, after trying to get opCmp to work, I was missing a piece --  
toHash! I couldn't get the thing to only store one key!

So I have to update my requirements. Here are the two cases where a struct  
T should be usable as an AA key:

1. Neither opCmp nor opEquals are defined (and defaults are generated).
2. Both opEquals and toHash are defined.

Any other key types should be disallowed.

-Steve