Variable to char\byte array

Hello everyone,

Im not sure if you can do this in c++ but here it is. I have a function that has 4 parameters. The first parameter is a variable (like int64 or int 32) or a byte array. My question is how to handle it. Can I typecast the passed variables into char/byte array? 

If this doesnt work, how can I handle a function parameter if Im not sure of the type?

Mike