Trait InsertOpt

pub trait InsertOpt<K: Eq + Hash, V> {
    // Required method
    fn insert_opt(&mut self, key: impl Into<K>, value: Option<impl Into<V>>);
}

Required Methods

fn insert_opt(&mut self, key: impl Into<K>, value: Option<impl Into<V>>)

Insert an item only if it exists

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<K: Eq + Hash, V> InsertOpt<K, V> for HashMap<K, V>

fn insert_opt(&mut self, key: impl Into<K>, value: Option<impl Into<V>>)

Implementors