#![allow(dead_code)]

// A custom trait
trait MyTrait {
    fn print();
}

macro_rules! impl_my_trait {
    ($type:ident, $($tt:ident),*) => {
        impl<$type, $($tt),*> MyTrait for ($type, $($tt),*)
            where $type: MyTrait, $($tt: MyTrait),* {
                fn print() {
                    $type::print();
                    $($tt::print();)*
                }
            }
        impl_my_trait!($($tt),*);
    };
    ( $($tt:tt),* ) => {
        impl MyTrait for () {
            fn print() {}
        }
    }
}
// Implement the trait for 0 to 10 elements tuples.
impl_my_trait!(T00, T01, T02, T03, T04, T05, T06, T07, T08, T09);

// struct using the trait
macro_rules! impl_traits {
    ($type:ident, $($tt:ident),*) => {
        struct $type {}
        impl MyTrait for $type {
            fn print() { print!(stringify!($type)) }
        }
        impl_traits!($($tt),*);
    };
    ( $($tt:tt),* ) => { }
}
impl_traits!(T00, T01, T02, T03, T04, T05, T06, T07, T08, T09);

fn main() {
   <(T00, T01, T02)>::print();
   println!("");
   println!("----");
   <(T00, T01, T00)>::print(); // how to have a compile error here?
}