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Struct Cursor 

pub struct Cursor<'a, K, V>where
    K: 'a,
    V: 'a,{ /* private fields */ }
🔬This is a nightly-only experimental API. (btree_cursors #107540)

A cursor over a BTreeMap.

A Cursor is like an iterator, except that it can freely seek back-and-forth.

Cursors always point to a gap between two elements in the map, and can operate on the two immediately adjacent elements.

A Cursor is created with the BTreeMap::lower_bound and BTreeMap::upper_bound methods.

Implementations

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impl<'a, K, V> Cursor<'a, K, V>
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pub fn next(&mut self) -> Option<(&'a K, &'a V)>
🔬This is a nightly-only experimental API. (btree_cursors #107540)

Advances the cursor to the next gap, returning the key and value of the element that it moved over.

If the cursor is already at the end of the map then None is returned and the cursor is not moved.

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pub fn prev(&mut self) -> Option<(&'a K, &'a V)>
🔬This is a nightly-only experimental API. (btree_cursors #107540)

Advances the cursor to the previous gap, returning the key and value of the element that it moved over.

If the cursor is already at the start of the map then None is returned and the cursor is not moved.

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pub fn peek_next(&self) -> Option<(&'a K, &'a V)>
🔬This is a nightly-only experimental API. (btree_cursors #107540)

Returns a reference to the key and value of the next element without moving the cursor.

If the cursor is at the end of the map then None is returned.

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pub fn peek_prev(&self) -> Option<(&'a K, &'a V)>
🔬This is a nightly-only experimental API. (btree_cursors #107540)

Returns a reference to the key and value of the previous element without moving the cursor.

If the cursor is at the start of the map then None is returned.

Trait Implementations

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impl<K, V> Clone for Cursor<'_, K, V>
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fn clone(&self) -> Cursor<'_, K, V>
Returns a duplicate of the value. Read more
1.0.0Source
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from source. Read more
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impl<K, V> Debug for Cursor<'_, K, V>where
    K: Debug,
    V: Debug,
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fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>
Formats the value using the given formatter. Read more

Auto Trait Implementations

impl<'a, K, V> Freeze for Cursor<'a, K, V>
impl<'a, K, V> RefUnwindSafe for Cursor<'a, K, V>where
    K: RefUnwindSafe,
    V: RefUnwindSafe,
impl<'a, K, V> Send for Cursor<'a, K, V>where
    K: Sync,
    V: Sync,
impl<'a, K, V> Sync for Cursor<'a, K, V>where
    K: Sync,
    V: Sync,
impl<'a, K, V> Unpin for Cursor<'a, K, V>
impl<'a, K, V> UnwindSafe for Cursor<'a, K, V>where
    K: RefUnwindSafe,
    V: RefUnwindSafe,

Blanket Implementations

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impl<T> Any for Twhere
    T: 'static + ?Sized,
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fn type_id(&self) -> TypeId
Gets the TypeId of self. Read more
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impl<T> Borrow<T> for Twhere
    T: ?Sized,
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fn borrow(&self) -> &T
Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for Twhere
    T: ?Sized,
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fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
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impl<T> CloneToUninit for Twhere
    T: Clone,
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unsafe fn clone_to_uninit(&self, dest: *mut u8)
🔬This is a nightly-only experimental API. (clone_to_uninit #126799)
Performs copy-assignment from self to dest. Read more
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impl<T> From<T> for T
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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for Twhere
    U: From<T>,
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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> ToOwned for Twhere
    T: Clone,
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type Owned = T
The resulting type after obtaining ownership.
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fn to_owned(&self) -> T
Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)
Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T, U> TryFrom<U> for Twhere
    U: Into<T>,
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type Error = Infallible
The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
Performs the conversion.
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impl<T, U> TryInto<U> for Twhere
    U: TryFrom<T>,
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type Error = <U as TryFrom<T>>::Error
The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
Performs the conversion.

© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/collections/btree_map/struct.Cursor.html