mixed Set (string name, mixed arg [, int sc])
Using this function automatically takes care if the requested property is implemented 'hard' (by a function Set<name>()) or 'soft' (as a value in a mapping).
Hardcoded properties may deny a change of the properties value and may thus return a value different from 'arg'
#include <properties.h> obj->Set(P_VALUE, 100); /* sets the <obj> value to 100 coins. */