Type Alias First

pub type First<List> = <List as NonEmpty>::First;

Type-level ‘function’ to return the first element of a TList

Only implemented for non-empty TLists.

use tlist::*;
use typenum::consts::{U1, U2, U3};
use static_assertions::assert_type_eq_all as assert_type_eq;

assert_type_eq!(First<TList![U1, U2, U3]>, U1);

assert_type_eq!(First<TList![i8, usize, i32, u64]>, i8);