core::ops::deref::DerefMut

A trait for dereferencing in mutable contexts. This trait is similar to Deref but specifically handles cases where the value accessed is mutable. Despite its name, DerefMut does NOT allow modifying the inner value - it only indicates that the container itself is mutable.

Signature

pub trait DerefMut

Examples

#[derive(Copy, Drop)]
struct MutWrapper {
    value: T
}

impl MutWrapperDerefMut> of DerefMut> {
    type Target = T;
    fn deref_mut(ref self: MutWrapper) -> T {
        self.value
    }
}

// This will work since x is mutable
let mut x = MutWrapper { value: 42 };
let val = x.deref_mut();
assert!(val == 42);

// This would fail to compile since y is not mutable
let y = MutWrapper { value: 42 };
let val = y.deref_mut(); // Compile error

Trait functions

deref_mut

Returns the dereferenced value.

Signature

fn deref_mut(ref self: T) -> DerefMutTarget

Trait types

Target

The type of the dereferenced value.

Signature

type Target;