const/invariant

[Derek Parnell]

On Wed, 5 Dec 2007 10:00:28 -0500, Steven Schveighoffer wrote:

> "Denton Cockburn" wrote
>> given a class:
>>
>> class C {}
>>
>> what's the difference between:
>>
>> const C c = new C;
>> and
>> invariant C c = new C;
>>
>> From what I can see, neither are modifiable.  So what's different
>> (D2.008).
> 
> const class references can be used to call const member functions, but 
> cannot call normal member functions or invariant member functions.
> 
> invariant class references can be used to call const or invariant member 
> functions, but not normal member functions.
> 
> normal class references can call normal member functions and const member 
> functions, but not invariant member functions.

Thanks Steve, I guess this should be made clearer in the documentation.
Maybe a table such as ...

"Can Call" Table:
                           Member Function
Instance Declaration+----------------------------+
 -------------------| normal | const | invariant |
          ----------+--------+-------+-----------+
           normal   |   Y    |   Y   |     N     |
          ----------+--------+-------+-----------+
           const    |   N    |   Y   |     N     |
          ----------+--------+-------+-----------+
           invariant|   N    |   Y   |     Y     |
          ----------+--------+-------+-----------+



-- 
Derek
(skype: derek.j.parnell)
Melbourne, Australia
6/12/2007 9:41:44 AM