Manifest constants (was const again)

[Janice Caron]

On 12/8/07, Bill Baxter <dnewsgroup at billbaxter.com> wrote:
> For something with a literal syntax like strings I think the answer
> should be the same as the answer to what you get applying the operation
> to a literal.  So in the above case, "hello".ptr actually gives you an
> invariant(char)* also.  So that seems consistent.

...except that it breaks the analogy with #define.

In C, if I write a thousand lines of the form

    #define FOO "Bar"

then zero bytes of that will appear in the executable - /unless/ I
refer to one of those defined names in my program. Then, and only
then, will the bytes of the string be needed, and used. This allows
you to put lots and lots of strings in header files, safe in the
knowledge that they will not take up any space, unless you use them.
They are known at compile-time only, and if not used, are thrown away
at the end of compilation.

I don't know how that could work with enum strings. Maybe the string
is somehow called into existence whenever it's referenced - or maybe
the bytes of storage are used regardless? I'd be interested to know
the answer.