Enum http::header::Entry [−][src]
pub enum Entry<'a, T: 'a> {
Occupied(OccupiedEntry<'a, T>),
Vacant(VacantEntry<'a, T>),
}Expand description
A view into a single location in a HeaderMap, which may be vacant or occupied.
Variants
Occupied(OccupiedEntry<'a, T>)
Tuple Fields
0: OccupiedEntry<'a, T>An occupied entry
Vacant(VacantEntry<'a, T>)
Tuple Fields
0: VacantEntry<'a, T>A vacant entry
Implementations
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: HeaderMap<u32> = HeaderMap::default();
let headers = &[
"content-length",
"x-hello",
"Content-Length",
"x-world",
];
for &header in headers {
let counter = map.entry(header)
.or_insert(0);
*counter += 1;
}
assert_eq!(map["content-length"], 2);
assert_eq!(map["x-hello"], 1);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 = HeaderMap::new();
let res = map.entry("x-hello")
.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 = HeaderMap::new();
map.insert(HOST, "world".parse().unwrap());
let res = map.entry("host")
.or_insert_with(|| unreachable!());
assert_eq!(res, "world");Returns a reference to the entry’s key
Examples
let mut map = HeaderMap::new();
assert_eq!(map.entry("x-hello").key(), "x-hello");