alias this doesn't work for properties.

[JS]

On Friday, 2 August 2013 at 01:46:28 UTC, Jesse Phillips wrote:
> I'm going to provide a reduced case for the issue you are 
> having.
>
> struct Foo {
>     double x;
>     alias x this;
> }
>
> void main() {
>     Foo a;
>     a = 8; // Alias this assignment
>     assert(a.x == 8);
>     fun(7); // What you want
> }
>
> void fun(Foo a) {
> }
>
> You're claiming that since Foo is requested to "be" a double 
> calling fun(7) should just assign 7 to x.
>
> What you're missing is that it is Foo which behaves like 
> double, however fun(7) there is no Foo involved, it doesn't 
> exist. You're actually requesting that a Foo is created, then 
> to have an assignment of 7 to x of the new temporary Foo.
>
> This is not a bug, it is by design. Alias this is sugar of type 
> it is declared in not the type it is declared to.


Um, but I'm not talking about a free function or member function 
but a property... they are suppose to be special else whats the 
point. They are suppose to wrap fields.

Because of this "design" you speak of, I can't use a double 
wrapped(essentially)  type because it is in an interface and I 
can't use a field in the interface.

What is the difference between

class A
{
     int x;
}

class A
{
     private int _x;
     @property int x() { }
     @property int x(int v) { }
}

? From the outside world there is suppose to be no difference. 
The point of properties is to wrap a type... yet I can't do 
that.... and also because A is an interface there is not even a 
fallback to the using a field to get it to work.

Anyways, this isn't headed anywhere... It's easy to sit back and 
try to analyze the situation without having ran into the problem 
directly.