Enum nuclear::http::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>)
Expand description

An occupied entry

Vacant(VacantEntry<'a, T>)
Expand description

A vacant entry

Implementations

impl<'a, T> Entry<'a, T>[src]

pub fn or_insert(self, default: T) -> &'a mut T[src]

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);

pub fn or_insert_with<F>(self, default: F) -> &'a mut T where
    F: FnOnce() -> T, [src]

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");

pub fn key(&self) -> &HeaderName[src]

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

impl<'a, T> Debug for Entry<'a, T> where
    T: 'a + Debug, [src]

pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>[src]

Formats the value using the given formatter. Read more

Auto Trait Implementations

impl<'a, T> RefUnwindSafe for Entry<'a, T> where
    T: RefUnwindSafe, 

impl<'a, T> Send for Entry<'a, T> where
    T: Send, 

impl<'a, T> Sync for Entry<'a, T> where
    T: Sync, 

impl<'a, T> Unpin for Entry<'a, T>

impl<'a, T> !UnwindSafe for Entry<'a, T>

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized, [src]

pub fn type_id(&self) -> TypeId[src]

Gets the TypeId of self. Read more

impl<T> Borrow<T> for T where
    T: ?Sized, [src]

pub fn borrow(&self) -> &T[src]

Immutably borrows from an owned value. Read more

impl<T> BorrowMut<T> for T where
    T: ?Sized, [src]

pub fn borrow_mut(&mut self) -> &mut T[src]

Mutably borrows from an owned value. Read more

impl<T> From<T> for T[src]

pub fn from(t: T) -> T[src]

Performs the conversion.

impl<T> Instrument for T[src]

fn instrument(self, span: Span) -> Instrumented<Self>ⓘ

Notable traits for Instrumented<T>

impl<T> Future for Instrumented<T> where
    T: Future,  type Output = <T as Future>::Output;
[src]

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

fn in_current_span(self) -> Instrumented<Self>ⓘ

Notable traits for Instrumented<T>

impl<T> Future for Instrumented<T> where
    T: Future,  type Output = <T as Future>::Output;
[src]

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

impl<T, U> Into<U> for T where
    U: From<T>, [src]

pub fn into(self) -> U[src]

Performs the conversion.

impl<T, U> TryFrom<U> for T where
    U: Into<T>, [src]

type Error = Infallible

The type returned in the event of a conversion error.

pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>[src]

Performs the conversion.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, [src]

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>[src]

Performs the conversion.