Trait frunk_core::hlist::Selector

pub trait Selector<S, I> {
    // Required methods
    fn get(&self) -> &S;
    fn get_mut(&mut self) -> &mut S;
}

Trait for borrowing an HList element by type

This trait is part of the implementation of the inherent method HCons::get. Please see that method for more information.

You only need to import this trait when working with generic HLists of unknown type. If you have an HList of known type, then list.get() should “just work” even without the trait.

Required Methods

fn get(&self) -> &S

Borrow an element by type from an HList.

Please see the inherent method for more information.

The only difference between that inherent method and this trait method is the location of the type parameters (here, they are on the trait rather than the method).

fn get_mut(&mut self) -> &mut S

Mutably borrow an element by type from an HList.

Please see the inherent method for more information.

The only difference between that inherent method and this trait method is the location of the type parameters (here, they are on the trait rather than the method).

Implementors

impl<Head, Tail, FromTail, TailIndex> Selector<FromTail, There<TailIndex>> for HCons<Head, Tail>

where Tail: Selector<FromTail, TailIndex>,

impl<T, Tail> Selector<T, Here> for HCons<T, Tail>