pub trait Extend<A> {
// Required method
fn extend<T>(&mut self, iter: T)
where T: IntoIterator<Item = A>;
// Provided methods
fn extend_one(&mut self, item: A) { ... }
fn extend_reserve(&mut self, additional: usize) { ... }
}
Expand description
Extend a collection with the contents of an iterator.
Iterators produce a series of values, and collections can also be thought
of as a series of values. The Extend
trait bridges this gap, allowing you
to extend a collection by including the contents of that iterator. When
extending a collection with an already existing key, that entry is updated
or, in the case of collections that permit multiple entries with equal
keys, that entry is inserted.
§Examples
Basic usage:
// You can extend a String with some chars:
let mut message = String::from("The first three letters are: ");
message.extend(&['a', 'b', 'c']);
assert_eq!("abc", &message[29..32]);
Implementing Extend
:
// A sample collection, that's just a wrapper over Vec<T>
#[derive(Debug)]
struct MyCollection(Vec<i32>);
// Let's give it some methods so we can create one and add things
// to it.
impl MyCollection {
fn new() -> MyCollection {
MyCollection(Vec::new())
}
fn add(&mut self, elem: i32) {
self.0.push(elem);
}
}
// since MyCollection has a list of i32s, we implement Extend for i32
impl Extend<i32> for MyCollection {
// This is a bit simpler with the concrete type signature: we can call
// extend on anything which can be turned into an Iterator which gives
// us i32s. Because we need i32s to put into MyCollection.
fn extend<T: IntoIterator<Item=i32>>(&mut self, iter: T) {
// The implementation is very straightforward: loop through the
// iterator, and add() each element to ourselves.
for elem in iter {
self.add(elem);
}
}
}
let mut c = MyCollection::new();
c.add(5);
c.add(6);
c.add(7);
// let's extend our collection with three more numbers
c.extend(vec![1, 2, 3]);
// we've added these elements onto the end
assert_eq!("MyCollection([5, 6, 7, 1, 2, 3])", format!("{c:?}"));
Required Methods§
sourcefn extend<T>(&mut self, iter: T)where
T: IntoIterator<Item = A>,
fn extend<T>(&mut self, iter: T)where
T: IntoIterator<Item = A>,
Extends a collection with the contents of an iterator.
As this is the only required method for this trait, the trait-level docs contain more details.
§Examples
// You can extend a String with some chars:
let mut message = String::from("abc");
message.extend(['d', 'e', 'f'].iter());
assert_eq!("abcdef", &message);
Provided Methods§
sourcefn extend_one(&mut self, item: A)
fn extend_one(&mut self, item: A)
extend_one
)Extends a collection with exactly one element.
sourcefn extend_reserve(&mut self, additional: usize)
fn extend_reserve(&mut self, additional: usize)
extend_one
)Reserves capacity in a collection for the given number of additional elements.
The default implementation does nothing.
Object Safety§
Implementors§
impl Extend<(String, Value)> for geng::prelude::serde_json::Map<String, Value>
impl Extend<(String, Value)> for geng::prelude::toml::map::Map<String, Value>
impl Extend<char> for String
impl Extend<u8> for Bytes
impl Extend<u8> for bytes::bytes::BytesMut
impl Extend<u8> for BytesMut
impl Extend<()> for ()
impl Extend<Extensions> for Extensions
impl Extend<Box<str>> for String
impl Extend<String> for String
impl Extend<OsString> for OsString
impl Extend<Access> for Access
impl Extend<Access> for Access
impl Extend<AccessFlags> for AccessFlags
impl Extend<Anchor> for Anchor
impl Extend<Anchor> for Anchor
impl Extend<Api> for Api
impl Extend<AtFlags> for AtFlags
impl Extend<AtFlags> for AtFlags
impl Extend<AtFlags> for AtFlags
impl Extend<Bytes> for BytesMut
impl Extend<CapabilitiesSecureBits> for CapabilitiesSecureBits
impl Extend<Capability> for Capability
impl Extend<Capability> for Capability
impl Extend<Capability> for Capability
impl Extend<CapabilityFlags> for CapabilityFlags
impl Extend<Channels> for Channels
impl Extend<ConfigSurfaceTypes> for ConfigSurfaceTypes
impl Extend<ConstraintAdjustment> for ConstraintAdjustment
impl Extend<ContentHint> for ContentHint
impl Extend<ContentHint> for ContentHint
impl Extend<ContentHint> for ContentHint
impl Extend<ControlModes> for ControlModes
impl Extend<CreateFlags> for CreateFlags
impl Extend<CreateFlags> for CreateFlags
impl Extend<CreateFlags> for CreateFlags
impl Extend<CreateFlags> for CreateFlags
impl Extend<DisplayFeatures> for DisplayFeatures
impl Extend<DndAction> for DndAction
impl Extend<DupFlags> for DupFlags
impl Extend<DupFlags> for DupFlags
impl Extend<EfdFlags> for EfdFlags
impl Extend<EfdFlags> for EfdFlags
impl Extend<EpollCreateFlags> for EpollCreateFlags
impl Extend<EpollCreateFlags> for EpollCreateFlags
impl Extend<EpollFlags> for EpollFlags
impl Extend<EpollFlags> for EpollFlags
impl Extend<EventFlags> for EventFlags
impl Extend<EventFlags> for EventFlags
impl Extend<EventMask> for EventMask
impl Extend<EventMask> for EventMask
impl Extend<EventfdFlags> for EventfdFlags
impl Extend<EventfdFlags> for EventfdFlags
impl Extend<FallocateFlags> for FallocateFlags
impl Extend<FallocateFlags> for FallocateFlags
impl Extend<FallocateFlags> for FallocateFlags
impl Extend<FdFlag> for FdFlag
impl Extend<FdFlags> for FdFlags
impl Extend<FdFlags> for FdFlags
impl Extend<Flags> for Flags
impl Extend<Flags> for Flags
impl Extend<Flags> for Flags
impl Extend<FloatingPointEmulationControl> for FloatingPointEmulationControl
impl Extend<FloatingPointExceptionMode> for FloatingPointExceptionMode
impl Extend<FsFlags> for FsFlags
impl Extend<FutexFlags> for FutexFlags
impl Extend<InputModes> for InputModes
impl Extend<Kind> for Kind
impl Extend<LocalModes> for LocalModes
impl Extend<MRemapFlags> for MRemapFlags
impl Extend<MapFlags> for MapFlags
impl Extend<MemFdCreateFlag> for MemFdCreateFlag
impl Extend<MembarrierQuery> for MembarrierQuery
impl Extend<MemfdFlags> for MemfdFlags
impl Extend<MemfdFlags> for MemfdFlags
impl Extend<MlockAllFlags> for MlockAllFlags
impl Extend<Mode> for Mode
impl Extend<Mode> for Mode
impl Extend<Mode> for Mode
impl Extend<Mode> for Mode
impl Extend<ModifiersState> for ModifiersState
impl Extend<MountFlags> for MountFlags
impl Extend<MountFlags> for MountFlags
impl Extend<MountPropagationFlags> for MountPropagationFlags
impl Extend<MountPropagationFlags> for MountPropagationFlags
impl Extend<MsFlags> for MsFlags
impl Extend<MsgFlags> for MsgFlags
impl Extend<OFlag> for OFlag
impl Extend<OFlags> for OFlags
impl Extend<OFlags> for OFlags
impl Extend<OutputModes> for OutputModes
impl Extend<PidfdFlags> for PidfdFlags
impl Extend<PidfdGetfdFlags> for PidfdGetfdFlags
impl Extend<PipeFlags> for PipeFlags
impl Extend<PipeFlags> for PipeFlags
impl Extend<PollFlags> for PollFlags
impl Extend<PollFlags> for PollFlags
impl Extend<PollFlags> for PollFlags
impl Extend<PortCap> for PortCap
impl Extend<PortType> for PortType
impl Extend<ProtFlags> for ProtFlags
impl Extend<ReadWriteFlags> for ReadWriteFlags
impl Extend<ReadWriteFlags> for ReadWriteFlags
impl Extend<RecvFlags> for RecvFlags
impl Extend<Remove> for Remove
impl Extend<RenameFlags> for RenameFlags
impl Extend<RenameFlags> for RenameFlags
impl Extend<RenameFlags> for RenameFlags
impl Extend<Resize> for Resize
impl Extend<ResolveFlags> for ResolveFlags
impl Extend<ResolveFlags> for ResolveFlags
impl Extend<SFlag> for SFlag
impl Extend<SealFlag> for SealFlag
impl Extend<SealFlags> for SealFlags
impl Extend<SealFlags> for SealFlags
impl Extend<SendFlags> for SendFlags
impl Extend<ShmOFlags> for ShmOFlags
impl Extend<SockFlag> for SockFlag
impl Extend<SocketFlags> for SocketFlags
impl Extend<SpeculationFeatureControl> for SpeculationFeatureControl
impl Extend<SpeculationFeatureState> for SpeculationFeatureState
impl Extend<SpliceFlags> for SpliceFlags
impl Extend<SpliceFlags> for SpliceFlags
impl Extend<StatVfsMountFlags> for StatVfsMountFlags
impl Extend<StatVfsMountFlags> for StatVfsMountFlags
impl Extend<StatxFlags> for StatxFlags
impl Extend<StatxFlags> for StatxFlags
impl Extend<Table> for ArrayOfTables
impl Extend<TaggedAddressMode> for TaggedAddressMode
impl Extend<ThreadNameSpaceType> for ThreadNameSpaceType
impl Extend<TimerfdFlags> for TimerfdFlags
impl Extend<TimerfdTimerFlags> for TimerfdTimerFlags
impl Extend<TimestampingFlag> for TimestampingFlag
impl Extend<TrancheFlags> for TrancheFlags
impl Extend<Transformations> for Transformations
impl Extend<Transient> for Transient
impl Extend<UnalignedAccessControl> for UnalignedAccessControl
impl Extend<UnmountFlags> for UnmountFlags
impl Extend<UnmountFlags> for UnmountFlags
impl Extend<WaitOptions> for WaitOptions
impl Extend<WaitidOptions> for WaitidOptions
impl Extend<WatchFlags> for WatchFlags
impl Extend<WatchFlags> for WatchFlags
impl Extend<WatchMask> for WatchMask
impl Extend<WatchMask> for WatchMask
impl Extend<WindowButtons> for WindowButtons
impl Extend<WindowManagerCapabilities> for WindowManagerCapabilities
impl Extend<WindowState> for WindowState
impl Extend<XattrFlags> for XattrFlags
impl Extend<XattrFlags> for XattrFlags
impl Extend<xkb_state_component> for xkb_state_component
impl<'a> Extend<&'a char> for String
impl<'a> Extend<&'a str> for String
impl<'a> Extend<&'a u8> for Bytes
impl<'a> Extend<&'a u8> for bytes::bytes::BytesMut
impl<'a> Extend<&'a u8> for BytesMut
impl<'a> Extend<&'a OsStr> for OsString
impl<'a> Extend<Cow<'a, str>> for String
impl<'a> Extend<Cow<'a, OsStr>> for OsString
impl<'a, K, V, A> Extend<(&'a K, &'a V)> for BTreeMap<K, V, A>
impl<'a, K, V, S> Extend<(&'a K, &'a V)> for geng::prelude::HashMap<K, V, S>
impl<'a, K, V, S> Extend<(&'a K, &'a V)> for IndexMap<K, V, S>
impl<'a, K, V, S> Extend<(&'a K, &'a V)> for AHashMap<K, V, S>
impl<'a, K, V, S, A> Extend<&'a (K, V)> for HashMap<K, V, S, A>
Inserts all new key-values from the iterator and replaces values with existing keys with new values returned from the iterator.
impl<'a, K, V, S, A> Extend<(&'a K, &'a V)> for HashMap<K, V, S, A>
Inserts all new key-values from the iterator and replaces values with existing keys with new values returned from the iterator.
impl<'a, T, A> Extend<&'a T> for BinaryHeap<T, A>
impl<'a, T, A> Extend<&'a T> for BTreeSet<T, A>
impl<'a, T, A> Extend<&'a T> for LinkedList<T, A>
impl<'a, T, A> Extend<&'a T> for VecDeque<T, A>
impl<'a, T, A> Extend<&'a T> for Vec<T, A>
Extend implementation that copies elements out of references before pushing them onto the Vec.
This implementation is specialized for slice iterators, where it uses copy_from_slice
to
append the entire slice at once.
impl<'a, T, S> Extend<&'a T> for geng::prelude::HashSet<T, S>
impl<'a, T, S> Extend<&'a T> for IndexSet<T, S>
impl<'a, T, S> Extend<&'a T> for AHashSet<T, S>
impl<'a, T, S, A> Extend<&'a T> for HashSet<T, S, A>
impl<'a, V> Extend<(usize, &'a V)> for VecMap<V>where
V: Copy,
impl<'s, T> Extend<T> for SliceVec<'s, T>
impl<'slice, 'fd> Extend<SendAncillaryMessage<'slice, 'fd>> for SendAncillaryBuffer<'_, 'slice, 'fd>
impl<A> Extend<<A as Array>::Item> for ArrayVec<A>where
A: Array,
impl<A> Extend<<A as Array>::Item> for SmallVec<A>where
A: Array,
impl<A> Extend<<A as Array>::Item> for TinyVec<A>where
A: Array,
impl<A, B, ExtendA, ExtendB> Extend<(A, B)> for (ExtendA, ExtendB)
impl<Fut> Extend<Fut> for FuturesOrdered<Fut>where
Fut: Future,
impl<Fut> Extend<Fut> for FuturesUnordered<Fut>
impl<K, V> Extend<(K, V)> for InlineTable
impl<K, V> Extend<(K, V)> for Table
impl<K, V, A> Extend<(K, V)> for BTreeMap<K, V, A>
impl<K, V, S> Extend<(K, V)> for geng::prelude::HashMap<K, V, S>
Inserts all new key-values from the iterator and replaces values with existing keys with new values returned from the iterator.
impl<K, V, S> Extend<(K, V)> for IndexMap<K, V, S>
impl<K, V, S> Extend<(K, V)> for AHashMap<K, V, S>
impl<K, V, S, A> Extend<(K, V)> for HashMap<K, V, S, A>
Inserts all new key-values from the iterator and replaces values with existing keys with new values returned from the iterator.
impl<L, R, A> Extend<A> for Either<L, R>
impl<P> Extend<P> for std::path::PathBuf
impl<P> Extend<P> for PathBufwhere
P: AsRef<Path>,
impl<St> Extend<St> for SelectAll<St>
impl<T> Extend<(Option<HeaderName>, T)> for HeaderMap<T>
impl<T> Extend<(HeaderName, T)> for HeaderMap<T>
impl<T> Extend<T> for Collection<T>where
T: HasId,
impl<T, A> Extend<T> for BinaryHeap<T, A>
impl<T, A> Extend<T> for BTreeSet<T, A>
impl<T, A> Extend<T> for LinkedList<T, A>where
A: Allocator,
impl<T, A> Extend<T> for VecDeque<T, A>where
A: Allocator,
impl<T, A> Extend<T> for Vec<T, A>where
A: Allocator,
impl<T, S> Extend<T> for geng::prelude::HashSet<T, S>
impl<T, S> Extend<T> for IndexSet<T, S>
impl<T, S> Extend<T> for AHashSet<T, S>
impl<T, S, A> Extend<T> for HashSet<T, S, A>
impl<T, const CAP: usize> Extend<T> for arrayvec::arrayvec::ArrayVec<T, CAP>
Extend the ArrayVec
with an iterator.
Panics if extending the vector exceeds its capacity.