[plt-scheme] Missing scheme_object_type

 From "Inside MzScheme":
The following are the Scheme_Type values for the standard types: 
....
* scheme_object_type -- SCHEME_OBJ_CLASS extracts the class, SCHEME_OBJ_DATA
extracts/sets the user pointer, and SCHEME_OBJ_FLAG extracts/sets the flag;
test for this type with SCHEME_OBJP

But there are NO such definitions in MzScheme source. Is this information
obsoleted?


-- 
Sergey Khorev
http://iamphet.nm.ru
You got the ball. You had it right there. Then ... you hit it away! And
 then ... you go and walk after it again! It's a dumb game!
 -- Bill Cosby