[][src]Trait frunk_core::hlist::LiftFrom

pub trait LiftFrom<T, I> {
    fn lift_from(part: T) -> Self;

Indexed type conversions of T -> Self with index I. This is a generalized version of From which for example allows the caller to use default values for parts of Self and thus "fill in the blanks".

LiftFrom is the reciprocal of LiftInto.

use frunk::lift_from;
use frunk::prelude::*;

type H = Hlist![(), usize, f64, (), bool];

let x = H::lift_from(42.0);
assert_eq!(x, hlist![(), 0, 42.0, (), false]);

let x: H = lift_from(true);
assert_eq!(x, hlist![(), 0, 0.0, (), true]);Run

Required Methods

Performs the indexed conversion.


impl<Head, Tail, ValAtIx, TailIx> LiftFrom<ValAtIx, There<TailIx>> for HCons<Head, Tail> where
    Head: Default,
    Tail: HList + LiftFrom<ValAtIx, TailIx>, 

impl<Prefix, Suffix> LiftFrom<Prefix, Suffixed<Suffix>> for <Prefix as Add<Suffix>>::Output where
    Prefix: HList + Add<Suffix>,
    Suffix: Default

impl<T, Tail> LiftFrom<T, Here> for HCons<T, Tail> where
    Tail: Default + HList