Function_Group

Function Group is a Function Overloading macro/hack for the rust programing language. The macro allows you to define multiple functions that take a variable number of arguments! Actually the functions still only take one argument, but they accept multiple types of tuples

```rust function_group! { fn add -> usize { (one : usize, two : usize) { one + two } (one : usize, two : usize, three: usize) { add((one, two)) + three } } }

assert!(add((5, 5)) == 10); assert!(add((5, 5, 5)) == 15); ```

Possible future features

1. Generics should be feasble on a per sub-function basis
2. having a function group in the impl block of a struct should be possible
3. having a function group in a trait is unlikely