Nested Structs

[d coder]

> A struct nested in a class does not have a hidden "outer" pointer as a
> nested class does.  It's because a struct is generally more bare-bones than
> a class (which has loads of hidden pieces: vtable, interfaces, classinfo,
> etc.).  Also, instantiating such a struct does not tie it to a class
> instance.
>

Thanks Steve

As far as I am concerned, this is a very limiting behavior wrt structs
nested inside classes. I have also observed that if you define a
constant (using enum for example) inside the enclosing class, the
constant remains visible in the nested struct too. So I believe the
language is making the hidden "outer" scope visible to the nested
struct (or maybe there is some other mechanism for enums that I am not
aware of).

> You need to implement this behavior on your own:
>

Actually I am trying to define a DSEL and the end users are not
typically programmers. I am in a situation where the end-user decides
the unit in an enclosing class (unit of length as an inch for example)
and later whenever he instantiates a line or a shape, the particular
unit is automatically considered at the time of instantiation. For my
application, I need value semantics and therefor using nested classes
in place of structs can not be considered.

Making the end-users pass the unit or its context (in form of this
pointer) everytime they instantiate a shape would be atrocious. It
would defeat the very purpose of letting the end-user define a unit.

I know I am not on the right mailing group, but I want to ask for this
particular language enhancement. I believe this would make the
behavior of the language more straight wrt nested structs inside
classes (are not these beasts expected to serve like nested classes or
even structs nested inside function scopes?). I hope my requirement is
generic enough and fits the bill for an enhancement request.

Regards
- Cherry