c++ less operator overload, which way to use?

Question

For example: in a C++ header file, if I defined a struct Record and I would like to use it for possible sorting so that I want to overload the less operator

Answer 1

They are essentially the same, other than the first being non-const and allowing you to modify itself.

I prefer the second for 2 reasons:

1. It doesn't have to be a friend.
2. lhs does not have to be a Record