macro_rules! for_each_tuple_ {
    ($m:ident !!) => {
        $m! { }
    };
    ($m:ident !! $h:ident, $($t:ident,)*) => {
        $m! { $h, $($t,)* }
        $crate::macros::for_each_tuple_! { $m !! $($t,)* }
    }
}

macro_rules! for_each_tuple {
    ($m:ident) => {
        $crate::macros::for_each_tuple_! { $m !! T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18, T19, T20, }
    }
}

pub(crate) use for_each_tuple;
pub(crate) use for_each_tuple_;