Fully transitive const is not necessary

[Walter Bright]

Janice Caron wrote:
> On 02/04/2008, Jason House <jason.james.house at gmail.com> wrote:
>> And how do global variables fit into that?  Technically, they're always
>>  reachable and never inherit const.
> 
> Global variables will /not/ be reachable from a pure function. Example:
> 
>     int g;
> 
>     pure int f()
>     {
>         return g; /*ERROR*/
>     }
> 
> The above will not compile, because global variables won't be
> available to pure functions.

That's right, unless they are invariant globals.