Trait VecExt

pub trait VecExt<T> {
    // Required methods
    fn resize_up_with<F>(&mut self, new_len: usize, f: F)
       where F: FnMut() -> T;
    fn remove_item<V>(&mut self, item: &V) -> Option<T>
       where T: PartialEq<V>;
}

Extension trait with useful methods for std::vec::Vec.

Required Methods

fn resize_up_with<F>(&mut self, new_len: usize, f: F)

where F: FnMut() -> T,

Resizes the Vec in-place if the provided new_len is greater than the current Vec length.

In simple words, this method only make vector bigger, but not smaller. Calling this method with a length smaller or equal to the current length will do nothing.

This method uses a closure to create new values on every push. If you’d rather Clone a given value, use resize_up. If you want to use the Default trait to generate values, you can pass Default::default() as the second argument.

Examples

use stdext::prelude::*;

let mut vec = vec![1, 2, 3];
vec.resize_up_with(5, Default::default);
assert_eq!(vec, [1, 2, 3, 0, 0]);

let mut vec = vec![];
let mut p = 1;
vec.resize_up_with(4, || { p *= 2; p });
assert_eq!(vec, [2, 4, 8, 16]);

let mut vec = vec![1, 2, 3];
vec.resize_up_with(1, Default::default);
assert_eq!(vec, [1, 2, 3]); // Resizing to smaller size does nothing.

fn remove_item<V>(&mut self, item: &V) -> Option<T>

where T: PartialEq<V>,

Removes the first instance of item from the vector if the item exists.

Based on the unstable vec_remove_item feature, which has been deprecated and will be removed.

Examples

use stdext::prelude::*;
let mut vec = vec![1, 2, 3, 1];

vec.remove_item(&1);

assert_eq!(vec, vec![2, 3, 1]);

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<T> VecExt<T> for Vec<T>

fn resize_up_with<F>(&mut self, new_len: usize, f: F)

where F: FnMut() -> T,

fn remove_item<V>(&mut self, item: &V) -> Option<T>

where T: PartialEq<V>,

Implementors