new DIP47: Outlining member functions of aggregates

[Dmitry Olshansky]

08-Sep-2013 16:02, Michel Fortin пишет:
> On 2013-09-07 17:00:05 +0000, Walter Bright <newshound2 at digitalmars.com>
> said:
>
>> Outlining of member functions is the practice of placing the
>> declaration of a member function in the struct/class/union, and
>> placing the definition of it at global scope in the module or even in
>> another module.
>>
>> http://wiki.dlang.org/DIP47
>
> About placing the definition in another module, you say that the
> definition when outlined in another module would have private access to
> the private members of the module of declaration. Does that mean that
> the definition has access to the private members of two modules at the
> same time, the one it is declared in and the one it is defined in? That
> seems strange to me.

Same here. This was the ugliest point.

[snip]

> I'd like to make a suggestion. If one goal is effectively to allow the
> implementation of a function to live in a separate file from its
> declaration, then we already have a mechanism for that: .di files. So
> I'd like to suggest this: allow a .d file to "import" its corresponding
> .di file. Then the .d file should only contain the missing definitions
> for what's declared in the hand-crafted .di file. That'd remove the
> dubious semantics of making the definition part of another module and
> would also allow outlining of global functions. And it also matches
> better the C++ model of header/implementation files.

> Also, I'd allow outlining only for this specific case where a .di file
> is imported by a .d file. This way you know for sure when you see a
> declaration without the definition in a .di file that this declaration
> is in the corresponding .d file and not anywhere else, making it easier
> to hunt it down.
>
> Example:
>
>      // test.di
>      module test;
>
>      class A {
>          void foo(int a, int b);
>      }
>
>      // test.d
>      import module test; // import declarations from the .di file
>
>      void A.foo(int a, int b) {
>          // member function definition
>      }
>

With this suggestion it finally becomes sane.

-- 
Dmitry Olshansky