pub enum Entry<'a, VE: ValueEncoding> {
Occupied(OccupiedEntry<'a, VE>),
Vacant(VacantEntry<'a, VE>),
}
Expand description
A view into a single location in a MetadataMap
, which may be vacant or
occupied.
Variants§
Implementations§
source§impl<'a, VE: ValueEncoding> Entry<'a, VE>
impl<'a, VE: ValueEncoding> Entry<'a, VE>
sourcepub fn or_insert(self, default: MetadataValue<VE>) -> &'a mut MetadataValue<VE>
pub fn or_insert(self, default: MetadataValue<VE>) -> &'a mut MetadataValue<VE>
Ensures a value is in the entry by inserting the default if empty.
Returns a mutable reference to the first value in the entry.
§Examples
let mut map: MetadataMap = MetadataMap::default();
let keys = &[
"content-length",
"x-hello",
"Content-Length",
"x-world",
];
for &key in keys {
let counter = map.entry(key)
.expect("valid key names")
.or_insert("".parse().unwrap());
*counter = format!("{}{}", counter.to_str().unwrap(), "1").parse().unwrap();
}
assert_eq!(map.get("content-length").unwrap(), "11");
assert_eq!(map.get("x-hello").unwrap(), "1");
sourcepub fn or_insert_with<F: FnOnce() -> MetadataValue<VE>>(
self,
default: F,
) -> &'a mut MetadataValue<VE>
pub fn or_insert_with<F: FnOnce() -> MetadataValue<VE>>( self, default: F, ) -> &'a mut MetadataValue<VE>
Ensures a value is in the entry by inserting the result of the default function if empty.
The default function is not called if the entry exists in the map. Returns a mutable reference to the first value in the entry.
§Examples
Basic usage.
let mut map = MetadataMap::new();
let res = map.entry("x-hello").unwrap()
.or_insert_with(|| "world".parse().unwrap());
assert_eq!(res, "world");
The default function is not called if the entry exists in the map.
let mut map = MetadataMap::new();
map.insert("host", "world".parse().unwrap());
let res = map.entry("host")
.expect("host is a valid string")
.or_insert_with(|| unreachable!());
assert_eq!(res, "world");
sourcepub fn key(&self) -> &MetadataKey<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");
Trait Implementations§
Auto Trait Implementations§
impl<'a, VE> !Freeze for Entry<'a, VE>
impl<'a, VE> RefUnwindSafe for Entry<'a, VE>where
VE: RefUnwindSafe,
impl<'a, VE> Send for Entry<'a, VE>where
VE: Send,
impl<'a, VE> Sync for Entry<'a, VE>where
VE: Sync,
impl<'a, VE> Unpin for Entry<'a, VE>where
VE: Unpin,
impl<'a, VE> !UnwindSafe for Entry<'a, VE>
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
source§impl<T> Instrument for T
impl<T> Instrument for T
source§fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
source§fn in_current_span(self) -> Instrumented<Self> ⓘ
fn in_current_span(self) -> Instrumented<Self> ⓘ
source§impl<T> IntoRequest<T> for T
impl<T> IntoRequest<T> for T
source§fn into_request(self) -> Request<T>
fn into_request(self) -> Request<T>
Wrap the input message
T
in a tonic::Request