Operator overloading in Fortran with no object creation such as in friend functions (C++)

Question

I would like to know if there is anything similar to a "friend function", from C++, in Fortran. I would like to be able to make operator overloading without creating new objects since it is too expensive. I have already tried creating objects in a module and trying to make the overloaded operator return it, but it was not successful.

Answer 1

Your understanding of what friend means in C++ is incorrect. That deals with the accessibility of private class members inside the friend function - not with object creation as part of operator overloading. Fortran's accessibility model is different - any procedure defined in the same module as a type is a "friend" and there is nothing equivalent, in accessibility terms, to a member function.

The semantics of expression evaluation in both languages requires that the source implementation of an operator create a new object to store the result of the operation. Fancy compiler optimisation may prevent the actual creation of a temporary for a function result in some cases, but that very much depends on details.