In C++ make sure to always copy all of your data members in the copy constructor and copy assignment. If you have derived classes, make sure to invoke your base class copy constructor.
As of 7/15 I have been working on Collision Detection between 3D objects. Initially I was using the SAT (Separation Axis Test) algorithm to detect collision between objects but decided that it would be better to use the GJK (Gilbert-Johnson-Keerthi) + EPA (Expanding Polytope Algorithm) instead.
What does *const* mean? it simply informs the compiler and other programmers that a variable should not be modified. Reading Efficient C++, I came across a nice tip that I have been trying to implement in my game engine: Use const whenever possible.