Enum hyper::header::Entry[][src]

pub enum Entry<'a, T> where
    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>)

An occupied entry

Tuple Fields of Occupied

0: OccupiedEntry<'a, T>
Vacant(VacantEntry<'a, T>)

A vacant entry

Tuple Fields of Vacant

0: VacantEntry<'a, T>

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");

Trait Implementations

Formats the value using the given formatter. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Performs the conversion.

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more

Instruments this type with the current Span, returning an Instrumented wrapper. Read more

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.

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