Pass by value or reference, to a C++ constructor that needs to store a copy?

Question

Should a C++ (implicit or explicit) value constructor accept its parameter(s) by value or reference-to-const, when it needs to store a copy of the argument(s) in its object

Answer 1

Stylistically, I'd say that passing by reference is the better way.

If the performance really matters, then don't guess. Measure it.