Manifest constants (was const again)

[Bruce Adams]

On Sat, 08 Dec 2007 19:44:50 -0000, Janice Caron <caron800 at googlemail.com>  
wrote:

> On 12/8/07, Walter Bright <newshound1 at digitalmars.com> wrote:
>> No, that would be:
>>
>>      enum defname = "upload.log";
>>      enum float fudge = 61.74;
>>      enum char starter = 'r';
>>      enum qwerty = 0xF4;
>>      enum foobar = SomeFunc("foobar");
>
> The first one is interesting. Can I do
>
>     enum s = "hello";
>     auto p = s.ptr;
>
> ?

You're just evil aren't you? If its a manifest constant you can't take its  
address
without making it manifest beyond the compiler. That means the .ptr  
property is not useable.
I think that should be a compile time error.

I don't really understand the problem myself.
I always thought it was common sense that a 'simple' constant should only  
take
up space:

1) If it is used
1a) if it is never used it should use no space
1b) if it is used only a few times its the compilers decision whether to  
place it in .bss
2) If you need to take the address of it

I had assumed this was the case in D.
I guess the problem is to do with modules. You don't know at compile time  
whether it will
be used. So I guess you do need a way to say don't use any space after all.