RAII, value classes and implicit conversion

[Bill Baxter]

Chris Nicholson-Sauls wrote:
>>
>> Structs are a lot like classes, except they can NOT:
>> - have virtual methods
>> - override inherited methods
>> (technically: they can't have VMT table)
> 
> While in a certain sense true... I'd really like to avoid the C++ 
> situation where the only difference is where they get allocated. 

The only difference between struct and class in C++ is the default 
protection level.  In a struct memebers are public by default, for 
classes they're private by default.  That's the only difference.  And 
also the inheritance in structs is public by default, and private for 
classes.

And that's why it's really annoying that you can't generically forward 
declare a class/struct without knowing which it is.

   ---foo.h----
   class ForwardDeclared;
   class Foo {
      ForwardDeclared *f;
   };
   ------------

This fails if ForwardDeclared turns out to be a struct.  Grrr.  Who 
cares which it is?!  They're the same freaking thing!  All you need to 
know, mr. dumb compiler, is that I've got a pointer, period.

(Maybe typename fixes this?  Does anyone know?).

--bb