Trait Length 

pub trait Length {
    // Required method
    fn len(&self) -> usize;

    // Provided method
    fn is_empty(&self) -> bool { ... }
}

The length (or number of elements) of a collection.

Required Methods

fn len(&self) -> usize

Returns the number of elements in the collection, also referred to as its length.

Provided Methods

fn is_empty(&self) -> bool

Returns true if there are no elements in the collection.

Implementations on Foreign Types

impl Length for &str

fn len(&self) -> usize

impl Length for String

fn len(&self) -> usize

impl Length for BooleanBuffer

Available on crate feature arrow-rs only.

fn len(&self) -> usize

impl Length for NullBuffer

Available on crate feature arrow-rs only.

fn len(&self) -> usize

impl<T> Length for &[T]

fn len(&self) -> usize

impl<T> Length for &mut [T]

fn len(&self) -> usize

impl<T> Length for [T]

fn len(&self) -> usize

impl<T> Length for Box<[T]>

fn len(&self) -> usize

impl<T> Length for VecDeque<T>

fn len(&self) -> usize

impl<T> Length for Rc<[T]>

fn len(&self) -> usize

impl<T> Length for Arc<[T]>

fn len(&self) -> usize

impl<T> Length for IntoIter<T>

fn len(&self) -> usize

impl<T> Length for Vec<T>

fn len(&self) -> usize

impl<T> Length for Iter<'_, T>

fn len(&self) -> usize

impl<T: FixedSize> Length for ScalarBuffer<T>

Available on crate feature arrow-rs only.

fn len(&self) -> usize

impl<T: FixedSize> Length for BufferBuilder<T>

Available on crate feature arrow-rs only.

fn len(&self) -> usize

impl<T: Length> Length for Option<T>

fn len(&self) -> usize

impl<const N: usize, T> Length for [T; N]

fn len(&self) -> usize

Implementors

impl Length for VariableSizeBinary

impl<Buffer: BufferType> Length for Bitmap<Buffer>

impl<K: ArrayType<K>, V: ArrayType<V>, Buffer: BufferType> Length for KeyValueArray<K, V, Buffer>

where <K as ArrayType<K>>::Array<Buffer, NA, NA>: Length, <V as ArrayType<V>>::Array<Buffer, NA, NA>: Length,

Available on crate feature map only.

impl<Nullable: Nullability, Buffer: BufferType> Length for BooleanArray<Nullable, Buffer>

where Nullable::Collection<Bitmap<Buffer>, Buffer>: Length,

impl<Nullable: Nullability, OffsetItem: Offset, Buffer: BufferType> Length for StringArray<Nullable, OffsetItem, Buffer>

where VariableSizeBinaryArray<Nullable, OffsetItem, Buffer>: Length,

impl<Nullable: Nullability, OffsetItem: Offset, Buffer: BufferType> Length for VariableSizeBinaryArray<Nullable, OffsetItem, Buffer>

where Offsets<FixedSizePrimitiveArray<u8, NonNullable, Buffer>, Nullable, OffsetItem, Buffer>: Length,

impl<T, Nulls: Nullability, OffsetItem: Offset, Buffer: BufferType> Length for OffsetSlice<'_, T, Nulls, OffsetItem, Buffer>

impl<T, OffsetItem: Offset, Buffer: BufferType> Length for Offsets<T, NonNullable, OffsetItem, Buffer>

impl<T, OffsetItem: Offset, Buffer: BufferType> Length for Offsets<T, Nullable, OffsetItem, Buffer>

impl<T: Array, Nullable: Nullability, OffsetItem: Offset, Buffer: BufferType> Length for VariableSizeListArray<T, Nullable, OffsetItem, Buffer>

where Offsets<T, Nullable, OffsetItem, Buffer>: Length,

impl<T: StructArrayType, Nullable: Nullability, Buffer: BufferType> Length for StructArray<T, Nullable, Buffer>

where Nullable::Collection<<T as StructArrayType>::Array<Buffer>, Buffer>: Length,

impl<T: Unit> Length for Nulls<T>

impl<T: Unit, Nullable: Nullability, Buffer: BufferType> Length for NullArray<T, Nullable, Buffer>

where Nullable::Collection<Nulls<T>, Buffer>: Length,

impl<T: UnionArrayType<VARIANTS>, const VARIANTS: usize, Buffer: BufferType, OffsetItem: Offset> Length for DenseUnionArray<T, VARIANTS, Buffer, OffsetItem>

where for<'a> i8: From<&'a T>,

impl<T: UnionArrayType<VARIANTS>, const VARIANTS: usize, Buffer: BufferType, OffsetItem: Offset> Length for SparseUnionArray<T, VARIANTS, Buffer, OffsetItem>

where for<'a> i8: From<&'a T>,

impl<T: UnionArrayType<VARIANTS>, const VARIANTS: usize, UnionLayout: UnionType, Buffer: BufferType, OffsetItem: Offset> Length for UnionArray<T, VARIANTS, UnionLayout, Buffer, OffsetItem>

where for<'a> i8: From<&'a T>, <UnionLayout as UnionType>::Array<T, VARIANTS, Buffer, OffsetItem>: Length,

impl<T: LogicalArrayType<T>, Nullable: Nullability, Buffer: BufferType, OffsetItem: Offset, UnionLayout: UnionType> Length for LogicalArray<T, Nullable, Buffer, OffsetItem, UnionLayout>

where Option<T>: ArrayType<T>, Nullable::Item<T::ArrayType>: ArrayType<T::ArrayType>, <Nullable::Item<T::ArrayType> as ArrayType<T::ArrayType>>::Array<Buffer, OffsetItem, UnionLayout>: Length,

impl<T: FixedSize, Nullable: Nullability, Buffer: BufferType> Length for FixedSizePrimitiveArray<T, Nullable, Buffer>

where Nullable::Collection<Buffer::Buffer<T>, Buffer>: Length,

impl<const N: usize, Nullable: Nullability, Buffer: BufferType> Length for FixedSizeBinaryArray<N, Nullable, Buffer>

where FixedSizeListArray<N, FixedSizePrimitiveArray<u8, NonNullable, Buffer>, Nullable, Buffer>: Length,

impl<const N: usize, T: Array, Nullable: Nullability, Buffer: BufferType> Length for FixedSizeListArray<N, T, Nullable, Buffer>

where Nullable::Collection<T, Buffer>: Length,