# Trait alloc::borrow::BorrowMut

1.0.0 · source · [−]

    pub trait BorrowMut<Borrowed>: Borrow<Borrowed>where
        Borrowed: ?Sized,{
        fn borrow_mut(&mut self) -> &mut Borrowed;
    }

Expand description

A trait for mutably borrowing data.

As a companion to `Borrow<T>` this trait allows a type to borrow as an underlying type by providing a mutable reference. See `Borrow<T>` for more information on borrowing as another type.

## Required Methods

source

#### fn borrow_mut(&mut self) -> &mut Borrowed

Mutably borrows from an owned value.

##### Examples

    use std::borrow::BorrowMut;

    fn check<T: BorrowMut<[i32]>>(mut v: T) {
        assert_eq!(&mut [1, 2, 3], v.borrow_mut());
    }

    let v = vec![1, 2, 3];

    check(v);

Run

## Implementors

1.36.0 · source

### impl BorrowMut<str> for String

const: unstable · source

### impl<T> BorrowMut<T> for &mut Twhere
T: ?Sized,

const: unstable · source

### impl<T> BorrowMut<T> for Twhere
T: ?Sized,

source

### impl<T, A: Allocator> BorrowMut<[T]> for Vec<T, A>

1.4.0 (const: unstable) · source

### impl<T, const N: usize> BorrowMut<[T]> for [T; N]

1.1.0 · source

### impl<T: ?Sized, A: Allocator> BorrowMut<T> for Box<T, A>