Struct tower_grpc::metadata::VacantEntry

pub struct VacantEntry<'a, VE: ValueEncoding> { /* fields omitted */ }

A view into a single empty location in a MetadataMap.

This struct is returned as part of the Entry enum.

Methods

impl<'a, VE: ValueEncoding> VacantEntry<'a, VE>

pub fn key(&self) -> &MetadataKey<VE>

Returns a reference to the entry's key

Examples

let mut map = MetadataMap::new();

assert_eq!(map.entry("x-hello").unwrap().key(), "x-hello");

pub fn into_key(self) -> MetadataKey<VE>

Take ownership of the key

Examples

let mut map = MetadataMap::new();

if let Entry::Vacant(v) = map.entry("x-hello").unwrap() {
    assert_eq!(v.into_key().as_str(), "x-hello");
}

pub fn insert(self, value: MetadataValue<VE>) -> &'a mut MetadataValue<VE>

Insert the value into the entry.

The value will be associated with this entry's key. A mutable reference to the inserted value will be returned.

Examples

let mut map = MetadataMap::new();

if let Entry::Vacant(v) = map.entry("x-hello").unwrap() {
    v.insert("world".parse().unwrap());
}

assert_eq!(map.get("x-hello").unwrap(), "world");

pub fn insert_entry(self, value: MetadataValue<VE>) -> OccupiedEntry<'a, Ascii>

Insert the value into the entry.

The value will be associated with this entry's key. The new OccupiedEntry is returned, allowing for further manipulation.

Examples

let mut map = MetadataMap::new();

if let Entry::Vacant(v) = map.entry("x-hello").unwrap() {
    let mut e = v.insert_entry("world".parse().unwrap());
    e.insert("world2".parse().unwrap());
}

assert_eq!(map.get("x-hello").unwrap(), "world2");

Trait Implementations

impl<'a, VE: Debug + ValueEncoding> Debug for VacantEntry<'a, VE>

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.