Using ()s in @property functions

[Steven Schveighoffer]

On Tue, 29 Jun 2010 10:15:10 -0400, Leandro Lucarella <luca at llucax.com.ar>  
wrote:

> Steven Schveighoffer, el 29 de junio a las 08:13 me escribiste:
>> >>There is one thing that bugs me about this solution though.  What if  
>> the
>> >>user does this:
>> >>(1) Grab the pointer.  *ptr = prop;
>> >(1) Grab the pointer.  T* ptr = &prop;
>> >
>> >>(2) assigns to it.  *ptr = val;
>> >>(3) expects the result to be updated in prop.  assert(val == prop);
>> >
>>
>> Why would this assert fail?  If a property returns a ref
>
> What if it doesn't? If returns a temporary calculated value?

It returns a ref.  That can't be a calculated value.  If it's a calculated  
value then T* ptr = &prop will fail to compile.

>
>> then you
>> set through that ref.  What you did is no different, you just
>> delayed the assignment for a bit.
>>
>> You can reduce your test case to:
>>
>> (1) assign to the property.   prop = val;
>
> Is not the same at all! prop = val will call the setter function, *ptr
> = val will not!

Maybe you are thinking of something different, here is the code we're  
discussing:

struct Foo {
     uint num;

     @property ref uint front() {
         return num;
     }
}

-Steve