The @time macro "starts a timer" at the beginning of the code, and "stops the timer" when the code finishes. Elapsed time and memory usage is returned.
This macro doesn't allow the expression 2 + 2 to be evaluated at all. Instead, it reports which method would be used for these particular arguments. And it also tells you the source file that contains the method's definition, and the line number.
Show an expression and result, returning the result