Trait MutableValues

pub trait MutableValues: Sealed {
    type Value;

    // Required methods
    fn get_full_mut2<Q>(
        &mut self,
        value: &Q,
    ) -> Option<(usize, &mut Self::Value)>
       where Q: ?Sized + Hash + Equivalent<Self::Value>;
    fn get_index_mut2(&mut self, index: usize) -> Option<&mut Self::Value>;
    fn retain2<F>(&mut self, keep: F)
       where F: FnMut(&mut Self::Value) -> bool;
}

Opt-in mutable access to IndexSet values.

These methods expose &mut T, mutable references to the value as it is stored in the set. You are allowed to modify the values in the set if the modification does not change the value’s hash and equality.

If values are modified erroneously, you can no longer look them up. This is sound (memory safe) but a logical error hazard (just like implementing PartialEq, Eq, or Hash incorrectly would be).

use this trait to enable its methods for IndexSet.

This trait is sealed and cannot be implemented for types outside this crate.

Required Associated Types

type Value

Required Methods

fn get_full_mut2<Q>(&mut self, value: &Q) -> Option<(usize, &mut Self::Value)>

where Q: ?Sized + Hash + Equivalent<Self::Value>,

Return item index and mutable reference to the value

Computes in O(1) time (average).

fn get_index_mut2(&mut self, index: usize) -> Option<&mut Self::Value>

Return mutable reference to the value at an index.

Valid indices are 0 <= index < self.len().

Computes in O(1) time.

fn retain2<F>(&mut self, keep: F)

where F: FnMut(&mut Self::Value) -> bool,

Scan through each value in the set and keep those where the closure keep returns true.

The values are visited in order, and remaining values keep their order.

Computes in O(n) time (average).

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.

Implementors

impl<T, S> MutableValues for IndexSet<T, S>

where S: BuildHasher,

Opt-in mutable access to IndexSet values.

See MutableValues for more information.

type Value = T