separate Files for classes 3/4 - invalid example

Question

The Reader is asked to create a function test for a class demo without a return type. this is possible only for the constructor but not for demo:: test.

Answer 1

If you declare a funtion prototype in the class, you don't have to declare the data type later on, for implemention.

Answer 2

http://melpon.org/wandbox/permlink/EKFmZgfipVewSv6F