Trait hash_arr_map::IntoIndex[−][src]

pub trait IntoIndex {
    fn into_index(&self) -> Option<Idx<Self>>;
}
Expand description

An attempted conversion into an Idx.

This is used when converting a value into an appropriate index. Therefore, only types that are integer-like should return Some here.

Example:

use core::num::NonZeroUsize;

use hash_arr_map::{FromIndex, Idx, IntoIndex};

struct CouldBeAnIdx(i32);

impl IntoIndex for CouldBeAnIdx {
    fn into_index(&self) -> Option<Idx<Self>> {
        let nzu: NonZeroUsize = usize::try_from(self.0).ok()?.try_into().ok()?;
        Some(unsafe { Idx::new(nzu) })
    }
}

impl FromIndex for CouldBeAnIdx {
    fn from_index(idx: Idx<Self>) -> Self {
        Self(idx.get().get() as i32)
    }
}

Required methods

Try to convert self into an Idx.

use core::num::NonZeroUsize;

use hash_arr_map::{Idx, IntoIndex};

let a: i32 = 5;

assert_eq!(
    a.into_index(),
    Some(unsafe { Idx::new(NonZeroUsize::new(5).unwrap()) })
);

Implementations on Foreign Types

Implementors