I have more or less incidentally added a function to set the electrical charge of an object. I’m not doing much with it, yet, and so far my charges are limited to +1 and -1, but it’s there. I have successfully also managed to add a function to my physical system set up where I can change the size of an object. I wouldn’t normally want to do this except for testing purposes, but it needs to be there. The default size of an object on creation is now 1, so I need to be able to change it. It works so that I can’t expand an object to larger than the system or if there is crowding by a neighbor, but I can expand and contract them. I have a stub for atmospheric science and one for cell biology.
The sections on operator overloading, stream input/output, random access functions, inheritance, and polymorphism are going well. I have moved from structures into the wacky world of bit fiddling. This will be important along with the operator overloading when I go more deeply into arithmetic.