Trait tapir::Tap

pub trait Tap {
    fn tap<F: FnOnce(&mut Self)>(self, f: F) -> Self;
}

An interface to enable the tap operation which is implemented for all Sized types.

The tap operation takes full ownership of a variable, calls the given function with a mutable reference to the given variable and then returns full ownership of it. This allows for easy mutation without having to declare the variable as mutable.

Tapping can be used to reduce the amount of local mutable variables, which can make the code easier to read and may prevent accidental mutation.

Examples

fn get_unsorted_values() -> Vec<u32> {
    vec![42, 7, 1337, 69]
}

fn use_sorted_values(values: &[u32]) {
    assert_eq!(&[7, 42, 69, 1337], values);
}

// without tap one often needs mutable variables.
let mut old = get_unsorted_values();
old.sort();
use_sorted_values(&old);

// using tap, this can be simplified.
use tapir::Tap;

let tapped = get_unsorted_values().tap(|v| v.sort());
use_sorted_values(&tapped);

Required methods

fn tap<F: FnOnce(&mut Self)>(self, f: F) -> Self

Executes a closure on an object, returning it afterwards.

Examples

use tapir::Tap;

let mut max = 0;
let data: [u32; 5] = [2, 8, 3, 4, 0];
assert_eq!(
    data.tap(|x| x.sort()).tap(|x| max += x.last().unwrap()),
    [0, 2, 3, 4, 8]
);
assert_eq!(max, 8);

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Implementors

impl<T> Tap for T

fn tap<F: FnOnce(&mut Self)>(self, f: F) -> Self

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