I don’t inline anything until a profiler has specifically told me that not inlining is resulting in a performance problem.
The C++ compiler is very smart and will almost certainly automatically inline such simple function like this for you. And typically it’s smarter than you are and will do a much better job at determining what should or should not be inlined.
I would avoid thinking about what to or not to inline and focus on the solution. Adding the inline keyword later (which is not a guarantee of inline BTW) is very easy to do and potential places can be found readily with a profiler.