Struct FilterCount 

pub struct FilterCount {
    pub n_accepted: usize,
    pub n_rejected: usize,
}

A record of how many items a CountingFilter returned by IteratorExt::filter_cnt accepted and rejected.

In tor-guardmgr we use this type to keep track of which filters reject which guards.

Fields

n_accepted: usize

The number of items that the filter considered and accepted.

n_rejected: usize

The number of items that the filter considered and accepted.

Implementations

impl FilterCount

pub fn display_frac_rejected(&self) -> DisplayFracRejected<'_>

Return a wrapper that can be displayed as the fraction of rejected items.

Example

let mut count = FilterCount::default();
let sum_of_evens : u32 = (1..=10)
    .filter_cnt(&mut count, |x| *x % 2 == 0)
    .sum();
assert_eq!(format!("Rejected {} as odd", count.display_frac_rejected()),
    "Rejected 5/10 as odd".to_string());

pub fn count(&mut self, accept: bool) -> bool

Count and return the provided boolean value.

This is an alternative way to use FilterCount when you have to provide a function that takes a predicate rather than a member of an iterator chain.

Example

let mut count = FilterCount::default();
let mut emoji = "Hello 🙂 World 🌏!".to_string();
emoji.retain(|ch| count.count(!ch.is_ascii()));
assert_eq!(emoji, "🙂🌏");
assert_eq!(count, FilterCount { n_accepted: 2, n_rejected: 14});

Trait Implementations

impl Clone for FilterCount

fn clone(&self) -> FilterCount

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FilterCount

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

Formats the value using the given formatter.

impl Default for FilterCount

fn default() -> FilterCount

Returns the “default value” for a type.

impl PartialEq for FilterCount

fn eq(&self, other: &FilterCount) -> 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 Copy for FilterCount

impl Eq for FilterCount

impl StructuralPartialEq for FilterCount

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 16 bytes