Re: how come #include "*.cpp" works?

[mwoehlke <mwoehlke@tibco.com>]

Dave Korn wrote:
> On 24 May 2006 17:00, mwoehlke wrote:
>> 3: A create_<name> function must be written. If all objects were
>> constructed the same, this could have been lumped into the declaration
>> CREATABLE_CLASS macro, however not all constructors take the same
>> arguments, which is why 'create_<name>' takes an argc/argv pair. IOW
>> this requirement cannot be eliminated.
> 
>   Are you sure this can't be worked around using varargs macros?
> 
> #define CREATABLE_CLASS(name, ...) \
>   extern class OBJECT* create_##name( __VA_ARGS__ ); \

Hehe, good try :-), but "no"... First, how would you know how to invoke 
the create function like that? Second, 'argc' and 'argv' are actually 
being passed direct from the command line; the idea is that the 
individual create function deals with the args, so that the upper level 
doesn't need to know what the args should look like for a particular 
object type.

>> === For declaring an object
>> #define CREATABLE_CLASS(name) \
>> extern class OBJECT* create_##name( int argc, const char* argv[] ); \
>> class name : virtual public OBJECT
> 
>> === So main.cpp doesn't need the headers for every class
>> #undef CREATABLE_CLASS
>> #define CREATABLE_CLASS(name) \
>> extern class T_OBJ* create_##name( int argc, const char* argv[] );
>> #include "objects.def"
> 
>   Bad idea, I think.  You now have two separate bits of code that are
> generating the prototypes for this set of functions. [snip]

Oh, oops... it's actually 'T_OBJ' in my code; I was trying to replace it 
with 'OBJECT'. So, 'OBJECT' == 'T_OBJ'.

-- 
Matthew
Doom doom dooM doo-DooM dOOm DOom doOM... DOOM! -- Gir