# Struct reqwest::header::OccupiedEntry [−] [src]

    pub struct OccupiedEntry<'a, T> { /* fields omitted */ }

A view into a single occupied location in a `HeaderMap`.

This struct is returned as part of the `Entry` enum.

## Implementations

### `impl<'a, T> OccupiedEntry<'a, T>` [src]

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

Returns a reference to the entry’s key.

# Examples

    let mut map = HeaderMap::new();
    map.insert(HOST, "world".parse().unwrap());

    if let Entry::Occupied(e) = map.entry("host") {
        assert_eq!("host", e.key());
    }

#### `pub fn get(&self) -> &T` [src]

Get a reference to the first value in the entry.

Values are stored in insertion order.

# Panics

`get` panics if there are no values associated with the entry.

# Examples

    let mut map = HeaderMap::new();
    map.insert(HOST, "hello.world".parse().unwrap());

    if let Entry::Occupied(mut e) = map.entry("host") {
        assert_eq!(e.get(), &"hello.world");

        e.append("hello.earth".parse().unwrap());

        assert_eq!(e.get(), &"hello.world");
    }

#### `pub fn get_mut(&mut self) -> &mut T` [src]

Get a mutable reference to the first value in the entry.

Values are stored in insertion order.

# Panics

`get_mut` panics if there are no values associated with the entry.

# Examples

    let mut map = HeaderMap::default();
    map.insert(HOST, "hello.world".to_string());

    if let Entry::Occupied(mut e) = map.entry("host") {
        e.get_mut().push_str("-2");
        assert_eq!(e.get(), &"hello.world-2");
    }

#### `pub fn into_mut(self) -> &'a mut T` [src]

Converts the `OccupiedEntry` into a mutable reference to the first value.

The lifetime of the returned reference is bound to the original map.

# Panics

`into_mut` panics if there are no values associated with the entry.

# Examples

    let mut map = HeaderMap::default();
    map.insert(HOST, "hello.world".to_string());
    map.append(HOST, "hello.earth".to_string());

    if let Entry::Occupied(e) = map.entry("host") {
        e.into_mut().push_str("-2");
    }

    assert_eq!("hello.world-2", map["host"]);

#### `pub fn insert(&mut self, value: T) -> T` [src]

Sets the value of the entry.

All previous values associated with the entry are removed and the first one is returned. See `insert_mult` for an API that returns all values.

# Examples

    let mut map = HeaderMap::new();
    map.insert(HOST, "hello.world".parse().unwrap());

    if let Entry::Occupied(mut e) = map.entry("host") {
        let mut prev = e.insert("earth".parse().unwrap());
        assert_eq!("hello.world", prev);
    }

    assert_eq!("earth", map["host"]);

#### `pub fn insert_mult(&mut self, value: T) -> ValueDrain<'_, T>ⓘ

### Notable traits for ValueDrain<'a, T>

`impl<'a, T> Iterator for ValueDrain<'a, T> type Item = T;`
` [src]

Sets the value of the entry.

This function does the same as `insert` except it returns an iterator that yields all values previously associated with the key.

# Examples

    let mut map = HeaderMap::new();
    map.insert(HOST, "world".parse().unwrap());
    map.append(HOST, "world2".parse().unwrap());

    if let Entry::Occupied(mut e) = map.entry("host") {
        let mut prev = e.insert_mult("earth".parse().unwrap());
        assert_eq!("world", prev.next().unwrap());
        assert_eq!("world2", prev.next().unwrap());
        assert!(prev.next().is_none());
    }

    assert_eq!("earth", map["host"]);

#### `pub fn append(&mut self, value: T)` [src]

Insert the value into the entry.

The new value is appended to the end of the entry’s value list. All previous values associated with the entry are retained.

# Examples

    let mut map = HeaderMap::new();
    map.insert(HOST, "world".parse().unwrap());

    if let Entry::Occupied(mut e) = map.entry("host") {
        e.append("earth".parse().unwrap());
    }

    let values = map.get_all("host");
    let mut i = values.iter();
    assert_eq!("world", *i.next().unwrap());
    assert_eq!("earth", *i.next().unwrap());

#### `pub fn remove(self) -> T` [src]

Remove the entry from the map.

All values associated with the entry are removed and the first one is returned. See `remove_entry_mult` for an API that returns all values.

# Examples

    let mut map = HeaderMap::new();
    map.insert(HOST, "world".parse().unwrap());

    if let Entry::Occupied(e) = map.entry("host") {
        let mut prev = e.remove();
        assert_eq!("world", prev);
    }

    assert!(!map.contains_key("host"));

#### `pub fn remove_entry(self) -> (HeaderName, T)` [src]

Remove the entry from the map.

The key and all values associated with the entry are removed and the first one is returned. See `remove_entry_mult` for an API that returns all values.

# Examples

    let mut map = HeaderMap::new();
    map.insert(HOST, "world".parse().unwrap());

    if let Entry::Occupied(e) = map.entry("host") {
        let (key, mut prev) = e.remove_entry();
        assert_eq!("host", key.as_str());
        assert_eq!("world", prev);
    }

    assert!(!map.contains_key("host"));

#### `pub fn remove_entry_mult(self) -> (HeaderName, ValueDrain<'a, T>)` [src]

Remove the entry from the map.

The key and all values associated with the entry are removed and returned.

#### `pub fn iter(&self) -> ValueIter<'_, T>ⓘ

### Notable traits for ValueIter<'a, T>

`impl<'a, T> Iterator for ValueIter<'a, T> where
T: 'a, type Item = &'a T;`
` [src]

Returns an iterator visiting all values associated with the entry.

Values are iterated in insertion order.

# Examples

    let mut map = HeaderMap::new();
    map.insert(HOST, "world".parse().unwrap());
    map.append(HOST, "earth".parse().unwrap());

    if let Entry::Occupied(e) = map.entry("host") {
        let mut iter = e.iter();
        assert_eq!(&"world", iter.next().unwrap());
        assert_eq!(&"earth", iter.next().unwrap());
        assert!(iter.next().is_none());
    }

#### `pub fn iter_mut(&mut self) -> ValueIterMut<'_, T>ⓘ

### Notable traits for ValueIterMut<'a, T>

`impl<'a, T> Iterator for ValueIterMut<'a, T> where
T: 'a, type Item = &'a mut T;`
` [src]

Returns an iterator mutably visiting all values associated with the entry.

Values are iterated in insertion order.

# Examples

    let mut map = HeaderMap::default();
    map.insert(HOST, "world".to_string());
    map.append(HOST, "earth".to_string());

    if let Entry::Occupied(mut e) = map.entry("host") {
        for e in e.iter_mut() {
            e.push_str("-boop");
        }
    }

    let mut values = map.get_all("host");
    let mut i = values.iter();
    assert_eq!(&"world-boop", i.next().unwrap());
    assert_eq!(&"earth-boop", i.next().unwrap());

## Trait Implementations

### `impl<'a, T> Debug for OccupiedEntry<'a, T> where
T: Debug,` [src]

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

Formats the value using the given formatter. Read more

### `impl<'a, T> IntoIterator for OccupiedEntry<'a, T>` [src]

#### `type Item = &'a mut T`

The type of the elements being iterated over.

#### `type IntoIter = ValueIterMut<'a, T>`

Which kind of iterator are we turning this into?

#### `pub fn into_iter(self) -> ValueIterMut<'a, T>ⓘ

### Notable traits for ValueIterMut<'a, T>

`impl<'a, T> Iterator for ValueIterMut<'a, T> where
T: 'a, type Item = &'a mut T;`
` [src]

Creates an iterator from a value. Read more

### `impl<'a, 'b, T> IntoIterator for &'b OccupiedEntry<'a, T> where
'b: 'a,` [src]

#### `type Item = &'a T`

The type of the elements being iterated over.

#### `type IntoIter = ValueIter<'a, T>`

Which kind of iterator are we turning this into?

#### `pub fn into_iter(self) -> ValueIter<'a, T>ⓘ

### Notable traits for ValueIter<'a, T>

`impl<'a, T> Iterator for ValueIter<'a, T> where
T: 'a, type Item = &'a T;`
` [src]

Creates an iterator from a value. Read more

### `impl<'a, 'b, T> IntoIterator for &'b mut OccupiedEntry<'a, T> where
'b: 'a,` [src]

#### `type Item = &'a mut T`

The type of the elements being iterated over.

#### `type IntoIter = ValueIterMut<'a, T>`

Which kind of iterator are we turning this into?

#### `pub fn into_iter(self) -> ValueIterMut<'a, T>ⓘ

### Notable traits for ValueIterMut<'a, T>

`impl<'a, T> Iterator for ValueIterMut<'a, T> where
T: 'a, type Item = &'a mut T;`
` [src]

Creates an iterator from a value. Read more

## Auto Trait Implementations

### `impl<'a, T> RefUnwindSafe for OccupiedEntry<'a, T> where
T: RefUnwindSafe,`

### `impl<'a, T> Send for OccupiedEntry<'a, T> where
T: Send,`

### `impl<'a, T> Sync for OccupiedEntry<'a, T> where
T: Sync,`

### `impl<'a, T> Unpin for OccupiedEntry<'a, T>`

### `impl<'a, T> !UnwindSafe for OccupiedEntry<'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]

#### `pub fn instrument(self, span: Span) -> Instrumented<Self>` [src]

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

#### `pub fn in_current_span(self) -> Instrumented<Self>` [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.