Question

Why I can’t create or overload operator := in my class in C++?

Is there are some list operators that I can overload?

I can only overload, or also create some new custom operators?

Answer 1

Because no such operator exists in C++. You cannot roll your own operators because you would need to modify the grammar of the language for the parser to recognize them.

You can find a list of the available operators here or here (or better yet by reading the standard if you can get a copy).

Finally, be advised that overloading operators like there is no tomorrow is a mistake that pretty much every C++ beginner makes; operators are really nothing more than functions, and unless there is a very good case to be made for overloading an operator most of the time it’s a better idea to just write a plain function for your class instead. For example, std::string does not have an operator* even though it could be argued that it’s convenient to write

string sleepy = string("z") * 40;