Macro frunk::Hlist

macro_rules! Hlist {
    (  ) => { ... };
    ( ... $ Rest : ty ) => { ... };
    (
$ A : ty ) => { ... };
    (
$ A : ty , $ ( $ tok : tt ) * ) => { ... };
}

Returns a type signature for an HList of the provided types

This is a type macro (introduced in Rust 1.13) that makes it easier to write nested type signatures.

Examples

let h: Hlist!(f32, &str, Option<i32>) = hlist![13.5f32, "hello", Some(41)];

// Use "...Tail" to append another HList type at the end.
let h: Hlist!(f32, ...Hlist!(&str, Option<i32>)) = hlist![13.5f32, "hello", Some(41)];