I'm having a lot of trouble with operator overloading. I'm just not sure what it's used for, and when it should be used to generate a desired result. This closely ties with my confusion that, when creating a copy constructor (which, as I understand, is called whenever a function passes-by-value an object of the class type), it's generally understood that the = assignment operator should be overloaded and a destructor should be explicitly defined.
Any help would be greatly appreciated.
That's two questions. The one about the Rule of Three has been answered in another topic (spoiler: If you're implementing one of them, you're probably managing a resource and if you do, you should implement the other two to manage that resource right).
For a short answer on the use of operator overloading, compare the syntax for a matrix library that requires this:
M.multiply( a).plus( N).plus( A.multiply( B));
or even:
plus( plus( multiply( a, M), N), multiply( A,B));
with:
a * M + N + A * B;
