Struct BoxedFnConverter

pub struct BoxedFnConverter<L, R, EL = Infallible, ER = Infallible> { /* private fields */ }

A converter that uses boxed closures for conversions.

This is similar to FnConverter but uses trait objects, making its type always descriptable.

Example

use cached_pair::{Pair, boxed_fn_converter, BoxedFnConverter};
use std::convert::Infallible;
use std::num::TryFromIntError;

let converter = boxed_fn_converter(
    // Right to left
    |i: &i32| -> Result<u8, TryFromIntError> { (*i - 100).try_into() },
    // Left to right
    |u: &u8| -> Result<i32, Infallible> { Ok((*u as i32) + 100) },
);

// The type of the converter is descriptable! This is not the case with [`fn_converter()`].
let pair: Pair<u8, i32, BoxedFnConverter<u8, i32, TryFromIntError, Infallible>> =
    Pair::from_right_conv(142i32, converter);
assert_eq!(pair.try_left(), Ok(&42u8));

Trait Implementations

impl<L, R, EL, ER> Converter<L, R> for BoxedFnConverter<L, R, EL, ER>

type ToLeftError = EL

The error type returned when converting from right to left.

type ToRightError = ER

The error type returned when converting from left to right.

fn convert_to_left(&self, right: &R) -> Result<L, Self::ToLeftError>

Converts a reference to a right value into a left value.

fn convert_to_right(&self, left: &L) -> Result<R, Self::ToRightError>

Converts a reference to a left value into a right value.

impl<L, R, EL, ER> Debug for BoxedFnConverter<L, R, EL, ER>

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

Formats the value using the given formatter.