Struct ById

pub struct ById<T: ?Sized + Id>(pub T);

Newtype for references (or other types that implement Id) where equality is defined by the same method of the Id trait

Example

use refid::ById;
use std::collections::HashSet;
fn count_distinct<T>(slice: &[&T]) -> usize {
    let mut counted: HashSet<ById<&T>> = HashSet::new();
    let mut count: usize = 0;
    for item in slice {
        if counted.insert(ById(item)) {
            count += 1;
        }
    }
    count
}
let v1 = "X".to_string();
let v2 = "X".to_string();
let v3 = "X".to_string();
assert_eq!(count_distinct(&vec![&v1, &v2, &v1, &v3]), 3);

Tuple Fields

0: T

inner value (reference or other type that implements Id)

Trait Implementations

impl<T: Clone + ?Sized + Id> Clone for ById<T>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug + ?Sized + Id> Debug for ById<T>

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

Formats the value using the given formatter.

impl<T: ?Sized + Id> Hash for ById<T>

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T: ?Sized + Id> PartialEq for ById<T>

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: Copy + ?Sized + Id> Copy for ById<T>

impl<T: ?Sized + Id> Eq for ById<T>