Trait frunk::hlist::LiftFrom

pub trait LiftFrom<T, I> {
    pub 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]);

Required methods

pub fn lift_from(part: T) -> Self

Performs the indexed conversion.

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Implementors

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

pub fn lift_from(part: ValAtIx) -> HCons<Head, Tail>

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

pub fn lift_from(part: Prefix) -> <Prefix as Add<Suffix>>::Output

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

pub fn lift_from(part: T) -> HCons<T, Tail>

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