how come #include "*.cpp" works?

[mwoehlke]

Dave Korn wrote:
> On 18 May 2006 15:45, mwoehlke wrote:
> 
>> Anyway... what I do is have an "OBJ" ABC and subclass it for each type
>> of structure I want this program to be able to understand. What I want
>> to do is have some system that entails the fewest *lines* of code
>> (macros to turn one line into lots of *actual* code are OK) that can a:
>> construct an object by name, and b: provide me a list of names of
>> classes which can be created (i.e. if you enter an invalid one, it will
>> tell you valid ones). Any thoughts? (Maybe dropping a hippo on the code
>> will make it as small as I want it to be? ;-))
> 
>   Something like this?
(moved below)

Hey, that's pretty slick... thanks!

Upon further thought, I may actually do something with my Makefile and 
auto-generation of some file, but I think I'm still going to use part of 
this. (Having an entire class declaration inside of a macro kind-of rubs 
me wrong ;-). Also, I want to keep each class in its own header.)

-- 
Matthew
Hey, buddy, if it's OT, TITTTL!

--
> subclasses.def:
> ---------------
> 
> SUBCLASS (class1_name,
> 	void class1_func1 (int args, ... ); \
> 	int class1_func2 (int args, ... ); \
>            .... \
>        private: \
>        int m_foo; \
> )
> 
> SUBCLASS (class2_name,
> 	void class2_func1 (int args, ... ); \
> 	int class2_func2 (int args, ... ); \
>            .... \
>        private: \
>        void *m_foo; \
> )
> 
> subclass_list.cpp
> -----------------
> 
> #define SUBCLASS (A, B) { ## A , gen_ # A }
> 
> struct subclassdata {
> 	const char *name;
> 	ABC * (*gen_func)();
> };
> 
> const struct subclassdata subclasslist[] = {
> #include "subclasses.def"
> };
> 
> #undef SUBCLASS
> #define SUBCLASS (A, B) \
> ABC *gen_ # A () \
> { \
> 	return new A; \
> };
> 
> #include "subclasses.def"
> 
> 
> subclass_defns.h
> ----------------
> 
> #undef SUBCLASS
> #define SUBCLASS (A, B) \
> class A : public ABC { \
> B \
> };