Struct tonic::metadata::VacantEntry [−][src]
pub struct VacantEntry<'a, VE: ValueEncoding> { /* fields omitted */ }
Expand description
A view into a single empty location in a MetadataMap
.
This struct is returned as part of the Entry
enum.
Implementations
Returns a reference to the entry’s key
Examples
let mut map = MetadataMap::new();
assert_eq!(map.entry("x-hello").unwrap().key(), "x-hello");
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");
}
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");
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
Auto Trait Implementations
impl<'a, VE> RefUnwindSafe for VacantEntry<'a, VE> where
VE: RefUnwindSafe,
impl<'a, VE> Send for VacantEntry<'a, VE> where
VE: Send,
impl<'a, VE> Sync for VacantEntry<'a, VE> where
VE: Sync,
impl<'a, VE> Unpin for VacantEntry<'a, VE> where
VE: Unpin,
impl<'a, VE> !UnwindSafe for VacantEntry<'a, VE>
Blanket Implementations
Mutably borrows from an owned value. Read more
Attaches the provided Subscriber
to this type, returning a
WithDispatch
wrapper. Read more
Attaches the current default Subscriber
to this type, returning a
WithDispatch
wrapper. Read more