#ifndef DATATYPE
#define DATATYPE_SELF
#define DATATYPE(_class_,_variable_,_inherits_) extern class _class_ *_variable_
#endif
// ----------------------------------------------------
// data types

// sample data type is the MrType class, and we're making a variable called pMrType.
// this type does not inherit from another type, so we use 0.  If it did inherit from another single type,
// we would use the pointer to the definition of that type, such as pStringType











// ----------------------------------------------------
#ifdef DATATYPE_SELF
#undef DATATYPE_SELF
#undef DATATYPE
#endif