"passing two variables to the function one for the type and one for the size, or making different functions"

Yes, you will need 2 variables, but not type and size - the size is known implicitly once you have the type!

You will need to pass either
1. type (using some code of your own devising) and value, or
2. size and value.

Of course, for 'value', you could always pass a pointer!