Maintain notes for D's successor? [Was: Re: Why the @ in @safe? & UDAs]

[Timon Gehr]

On 11/08/2013 02:31 PM, Wyatt wrote:
>
> [3] http://wiki.dlang.org/DIP23 No, I won't ever give up. This is
> important. :<

Please do. Excerpts:

    struct S
    {
        @property Type foo();       // formal getter
        @property void bar(Type);   // formal setter
        @property ref Type baz();   // ref return getter == auxiliary setter
    }

    // Taking the address reveals the delegate
    static assert(is(typeof(&s.foo) == ref Type delegate()));
    // Changing precedence with parens reveals the returned type
    static assert(is(typeof(&(s.foo)) == Type*));

// ---

    struct S
    {
        Type foo();         // 0-arg function
        void bar(Type n);   // 1-arg function
        ref Type baz();     // 0-arg ref return function
    }
    // Getting address of delegate
    static assert(is(typeof(&s.baz) == ref Type delegate()));
    // Getting address of return
    static assert(is(typeof(&(s.baz)) == Type*));


It completely beats me how anyone can consider this a good idea. 
Seriously, this is broken. Furthermore, the DIP is too informal and 
fails to handle all relevant cases. I'd rather get rid of @property 
completely than to approve of DIP23.


See http://wiki.dlang.org/DIP24 (TLDR: The full proposal makes 
@properties behave like ordinary variables except that their address 
cannot be taken and there could be more postblit/destructor invocations 
in a given expression. There is a __traits to get the underlying 
getter/setter function symbols for properties.)