Trait nom::lib::std::ops::Index

pub trait Index<Idx> where
    Idx: ?Sized, {
    type Output: ?Sized;
    pub fn index(&self, index: Idx) -> &Self::Output;
}

[−] Expand description

Used for indexing operations (container[index]) in immutable contexts.

container[index] is actually syntactic sugar for *container.index(index), but only when used as an immutable value. If a mutable value is requested, IndexMut is used instead. This allows nice things such as let value = v[index] if the type of value implements Copy.

Examples

The following example implements Index on a read-only NucleotideCount container, enabling individual counts to be retrieved with index syntax.

use std::ops::Index;

enum Nucleotide {
    A,
    C,
    G,
    T,
}

struct NucleotideCount {
    a: usize,
    c: usize,
    g: usize,
    t: usize,
}

impl Index<Nucleotide> for NucleotideCount {
    type Output = usize;

    fn index(&self, nucleotide: Nucleotide) -> &Self::Output {
        match nucleotide {
            Nucleotide::A => &self.a,
            Nucleotide::C => &self.c,
            Nucleotide::G => &self.g,
            Nucleotide::T => &self.t,
        }
    }
}

let nucleotide_count = NucleotideCount {a: 14, c: 9, g: 10, t: 12};
assert_eq!(nucleotide_count[Nucleotide::A], 14);
assert_eq!(nucleotide_count[Nucleotide::C], 9);
assert_eq!(nucleotide_count[Nucleotide::G], 10);
assert_eq!(nucleotide_count[Nucleotide::T], 12);

Associated Types

type Output: ?Sized[−]

The returned type after indexing.

Required methods

pub fn index(&self, index: Idx) -> &Self::Output[−]

Performs the indexing (container[index]) operation.

Panics

May panic if the index is out of bounds.

Implementations on Foreign Types

impl Index<RangeFull> for CString

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type Output = CStr

pub fn index(&self, _index: RangeFull) -> &CStr

impl Index<RangeFull> for OsString

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type Output = OsStr

pub fn index(&self, _index: RangeFull) -> &OsStr

impl Index<RangeFrom<usize>> for CStr

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type Output = CStr

pub fn index(&self, index: RangeFrom<usize>) -> &CStr

impl<I> Index<I> for str where
    I: SliceIndex<str>, 

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type Output = <I as SliceIndex<str>>::Output

pub fn index(&self, index: I) -> &<I as SliceIndex<str>>::Output

impl<T, I> Index<I> for [T] where
    I: SliceIndex<[T]>, 

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type Output = <I as SliceIndex<[T]>>::Output

pub fn index(&self, index: I) -> &<I as SliceIndex<[T]>>::Output

impl<T, I, const N: usize> Index<I> for [T; N] where
    [T]: Index<I>, 

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type Output = <[T] as Index<I>>::Output

pub fn index(&self, index: I) -> &<[T; N] as Index<I>>::Output

Implementors

impl Index<Range<usize>> for String

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type Output = str

pub fn index(&self, index: Range<usize>) -> &str

impl Index<RangeFrom<usize>> for String

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type Output = str

pub fn index(&self, index: RangeFrom<usize>) -> &str

impl Index<RangeFull> for String

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type Output = str

pub fn index(&self, _index: RangeFull) -> &str

impl Index<RangeInclusive<usize>> for String

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type Output = str

pub fn index(&self, index: RangeInclusive<usize>) -> &str

impl Index<RangeTo<usize>> for String

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type Output = str

pub fn index(&self, index: RangeTo<usize>) -> &str

impl Index<RangeToInclusive<usize>> for String

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type Output = str

pub fn index(&self, index: RangeToInclusive<usize>) -> &str

impl<'_, K, Q, V> Index<&'_ Q> for BTreeMap<K, V> where
    K: Borrow<Q> + Ord,
    Q: Ord + ?Sized, 

type Output = V

pub fn index(&self, key: &Q) -> &V[−]

Returns a reference to the value corresponding to the supplied key.

Panics

Panics if the key is not present in the BTreeMap.

impl<'_, K, Q, V, S> Index<&'_ Q> for HashMap<K, V, S> where
    K: Eq + Hash + Borrow<Q>,
    Q: Eq + Hash + ?Sized,
    S: BuildHasher, 

type Output = V

pub fn index(&self, key: &Q) -> &V[−]

Returns a reference to the value corresponding to the supplied key.

Panics

Panics if the key is not present in the HashMap.

impl<A> Index<usize> for VecDeque<A>

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type Output = A

pub fn index(&self, index: usize) -> &A

impl<T, I, A> Index<I> for Vec<T, A> where
    I: SliceIndex<[T]>,
    A: Allocator, 

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type Output = <I as SliceIndex<[T]>>::Output

pub fn index(&self, index: I) -> &<Vec<T, A> as Index<I>>::Output

impl<T, S> Index<usize> for Rgb<T, S>

impl<T, C: AsRef<[T; 3]>> Index<usize> for AlphaColor<T, C>

impl<T> Index<usize> for Vec3<T>

impl<K: Key, T> Index<K> for KeyedDenseVec<K, T>

impl Index<usize> for FixedBitSet

impl<T> Index<Index> for Arena<T>

impl<'input, Endian> Index<usize> for EndianSlice<'input, Endian> where     Endian: Endianity,

impl<'input, Endian> Index<RangeFrom<usize>> for EndianSlice<'input, Endian> where     Endian: Endianity,

impl<I: Image> Index<u32> for Faces<I>

impl<K, Q: ?Sized, V, S> Index<&'_ Q> for HashMap<K, V, S> where     K: Eq + Hash + Borrow<Q>,     Q: Eq + Hash,     S: BuildHasher,

impl<Buffer> Index<(u8, u32, u32)> for FlatSamples<Buffer> where     Buffer: Index<usize>,

impl<P, Container> Index<(u32, u32)> for ImageBuffer<P, Container> where     P: Pixel + 'static,     P::Subpixel: 'static,     Container: Deref<Target = [P::Subpixel]>,

impl<T: Primitive> Index<usize> for Rgb<T>

impl<T: Primitive> Index<usize> for Bgr<T>

impl<T: Primitive> Index<usize> for Luma<T>

impl<T: Primitive> Index<usize> for Rgba<T>

impl<T: Primitive> Index<usize> for Bgra<T>

impl<T: Primitive> Index<usize> for LumaA<T>

impl<K, V, Q: ?Sized, S> Index<&'_ Q> for IndexMap<K, V, S> where     Q: Hash + Equivalent<K>,     K: Hash + Eq,     S: BuildHasher,

impl<K, V, S> Index<usize> for IndexMap<K, V, S>

impl<T, S> Index<usize> for IndexSet<T, S>

impl<N: Scalar, R: Dim, C: Dim, S: Storage<N, R, C>> Index<usize> for Matrix<N, R, C, S>

impl<N, R: Dim, C: Dim, S> Index<(usize, usize)> for Matrix<N, R, C, S> where     N: Scalar,     S: Storage<N, R, C>,

impl<N: Scalar, D: DimName> Index<usize> for Point<N, D> where     DefaultAllocator: Allocator<N, D>,

impl<N: Scalar, D: DimName> Index<(usize, usize)> for Rotation<N, D> where     DefaultAllocator: Allocator<N, D, D>,

impl<N: Scalar> Index<usize> for Quaternion<N>

impl<N: SimdRealField> Index<usize> for DualQuaternion<N>

impl<N: RealField, D, C: TCategory> Index<(usize, usize)> for Transform<N, D, C> where     D: DimName + DimNameAdd<U1>,     DefaultAllocator: Allocator<N, DimNameSum<D, U1>, DimNameSum<D, U1>>,

impl<N: RealField, T, BV> Index<DBVTLeafId> for DBVT<N, T, BV>

impl<N: RealField, T> Index<CollisionObjectSlabHandle> for CollisionObjectSlab<N, T>

impl<'a, C> Index<&'a (usize, usize)> for Matrix<C>

impl<N, E, Ty, Ix> Index<Ix> for Csr<N, E, Ty, Ix> where     Ty: EdgeType,     Ix: IndexType,

impl<N, E, Ty, Ix> Index<NodeIndex<Ix>> for Graph<N, E, Ty, Ix> where     Ty: EdgeType,     Ix: IndexType,

impl<N, E, Ty, Ix> Index<EdgeIndex<Ix>> for Graph<N, E, Ty, Ix> where     Ty: EdgeType,     Ix: IndexType,

impl<'a, G, I> Index<I> for Frozen<'a, G> where     G: Index<I>,

impl<N, E, Ty, Ix> Index<NodeIndex<Ix>> for StableGraph<N, E, Ty, Ix> where     Ty: EdgeType,     Ix: IndexType,

impl<N, E, Ty, Ix> Index<EdgeIndex<Ix>> for StableGraph<N, E, Ty, Ix> where     Ty: EdgeType,     Ix: IndexType,

impl<N, E, Ty> Index<(N, N)> for GraphMap<N, E, Ty> where     N: NodeTrait,     Ty: EdgeType,

impl<N, E, Ty: EdgeType, Null: Nullable<Wrapped = E>, Ix: IndexType> Index<NodeIndex<Ix>> for MatrixGraph<N, E, Ty, Null, Ix>

impl<N, E, Ty: EdgeType, Null: Nullable<Wrapped = E>, Ix: IndexType> Index<(NodeIndex<Ix>, NodeIndex<Ix>)> for MatrixGraph<N, E, Ty, Null, Ix>

impl<'t> Index<usize> for Captures<'t>

impl<'t, 'i> Index<&'i str> for Captures<'t>

impl<'t> Index<usize> for Captures<'t>

impl<'t, 'i> Index<&'i str> for Captures<'t>

impl<T> Index<usize> for Mesh<T>

impl<'a, T> Index<usize> for MeshSlice<'a, T>

impl<T: RealField> Index<usize> for Polyline<T>

impl<'a, T: RealField> Index<usize> for PolylineSlice<'a, T>

impl Index<TextureRef> for TexturesPool

impl Index<CubemapRef> for TexturesPool

impl Index<SamplerRef> for TexturesPool

impl<M: Key> Index<M> for MaterialPool<M>

impl<M: Key> Index<M> for MaterialCache<M>

impl Index<ProgramRef> for ProgramCache

impl Index<ShadowMapRef> for ShadowMapPool

impl<V: 'static, B: 'static> Index<AllocatorHandle<V, B>> for AllocatorsIndex

impl<T> Index<NodeId> for Arena<T>

impl Index<usize> for UniqueEntities

impl<'a, T: Index<U> + Clone, U: Clone> Index<U> for Property<'a, T>

impl<'a, T: Index<U> + Clone, U: Clone> Index<U> for PropertyLastValue<'a, T>

impl<'a, Q: ?Sized> Index<&'a Q> for Map<String, Value> where     String: Borrow<Q>,     Q: Ord + Eq + Hash,

impl<I> Index<I> for Value where     I: Index,

impl<T> Index<usize> for Slab<T>

impl<K: Key, V: Slottable> Index<K> for SlotMap<K, V>

impl<K: Key, V> Index<K> for DenseSlotMap<K, V>

impl<K: Key, V: Slottable> Index<K> for HopSlotMap<K, V>

impl<K: Key, V> Index<K> for SecondaryMap<K, V>

impl<K, V, S> Index<K> for SparseSecondaryMap<K, V, S> where     K: Key,     S: BuildHasher,

impl<A: Array, I: SliceIndex<[A::Item]>> Index<I> for SmallVec<A>

impl<T, P> Index<usize> for Punctuated<T, P>

impl<'a, Q: ?Sized> Index<&'a Q> for Map<String, Value> where     String: Borrow<Q>,     Q: Ord + Eq + Hash,

impl<I> Index<I> for Value where     I: Index,