EasyBMP | hpp source file class with support to build BMP images | Computer Vision library

You don't need to terminate every kind of array with NULL. In fact, strictly speaking not even char arrays need to be terminated with NULL. You can happily have non-NULL terminated arrays as long as you write your code so that you don't go beyond the end of the array.

Of course with char arrays there is an established convention such that many functions interpret a NULL valued char as the end of useful data. However that idea isn't established for any other type of array.

Or to say it a different way, NULL isn't a valid value for a struct (or a class, etc). While it is for a pointer to one, that's a completely different type. When you have an actual instance of a thing (such as a struct) it cannot be NULL.