Struct frunk::traits::Poly

pub struct Poly<T>(pub T);

Wrapper type around a function for polymorphic maps and folds.

This is a thin generic wrapper type that is used to differentiate between single-typed generic closures F that implements, say, Fn(i8) -> bool, and a Poly-typed F that implements multiple Function types via the Func trait. (say, Func<i8, Output=bool> and Func<bool, Output=f32>)

This is needed because there are completely generic impls for many of the HList traits that take a simple unwrapped closure.

Trait Implementations

impl<T> Clone for Poly<T> where
    T: Clone, 

fn clone(&self) -> Poly<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<P, R, CH, CTail> CoproductFoldable<Poly<P>, R> for Coproduct<CH, CTail> where
    CTail: CoproductFoldable<Poly<P>, R>,
    P: Func<CH, Output = R>, 

fn fold(self, f: Poly<P>) -> R

Use functions to fold a coproduct into a single value.

impl<T> Copy for Poly<T> where
    T: Copy, 

impl<T> Debug for Poly<T> where
    T: Debug, 

fn fmt(&self, f: &mut Formatter) -> Result<(), Error>

Formats the value using the given formatter.

impl<T> Default for Poly<T> where
    T: Default, 

fn default() -> Poly<T>

Returns the "default value" for a type.

impl<P, H, Tail> HMappable<Poly<P>> for HCons<H, Tail> where
    P: Func<H>,
    Tail: HMappable<Poly<P>>, 

type Output = HCons<<P as Func<H>>::Output, <Tail as HMappable<Poly<P>>>::Output>

fn map(self, poly: Poly<P>) -> <HCons<H, Tail> as HMappable<Poly<P>>>::Output

Apply a function to each element of an HList.