std::ops::DerefMut

Trait std::ops::DerefMut

#[lang = "deref_mut"]
pub trait DerefMut: Deref {
    fn deref_mut(&mut self) -> &mut Self::Target;
}

The DerefMut trait is used to specify the functionality of dereferencing mutably like *v = 1;

DerefMut also enables 'Deref coercions'.

Examples

A struct with a single field which is modifiable via dereferencing the struct.

use std::ops::{Deref, DerefMut};

struct DerefMutExample<T> {
    value: T
}

impl<T> Deref for DerefMutExample<T> {
    type Target = T;

    fn deref(&self) -> &T {
        &self.value
    }
}

impl<T> DerefMut for DerefMutExample<T> {
    fn deref_mut(&mut self) -> &mut T {
        &mut self.value
    }
}

fn main() {
    let mut x = DerefMutExample { value: 'a' };
    *x = 'b';
    assert_eq!('b', *x);
}

Required Methods

Implementors

• impl<'a, T> DerefMut for PeekMut<'a, T> where
    T: Ord, 
• impl DerefMut for String
• impl<T> DerefMut for Vec<T>
• impl<T> DerefMut for Box<T> where
    T: ?Sized, 
• impl<T> DerefMut for ManuallyDrop<T>
• impl<'a, T> DerefMut for &'a mut T where
    T: ?Sized, 
• impl<'b, T> DerefMut for RefMut<'b, T> where
    T: ?Sized, 
• impl<T> DerefMut for AssertUnwindSafe<T>
• impl<'mutex, T: ?Sized> DerefMut for MutexGuard<'mutex, T>
• impl<'rwlock, T: ?Sized> DerefMut for RwLockWriteGuard<'rwlock, T>