Trait enso_prelude::Index 1.0.0[−][src]
pub trait Index<Idx> where
Idx: ?Sized, { type Output: ?Sized; 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
Loading content...Required methods
Loading content...Implementations on Foreign Types
impl<I> Index<I> for str where
I: SliceIndex<str>,
[src]
impl<I> Index<I> for str where
I: SliceIndex<str>,
[src]type Output = <I as SliceIndex<str>>::Output
pub fn index(&self, index: I) -> &<I as SliceIndex<str>>::Output
[src]
impl Index<RangeInclusive<usize>> for String
[src]
impl Index<RangeInclusive<usize>> for String
[src]impl Index<RangeToInclusive<usize>> for String
[src]
impl Index<RangeToInclusive<usize>> for String
[src]impl<'a, K, V, S> Index<&'a <K as WeakElement>::Strong> for PtrWeakKeyHashMap<K, V, S> where
S: BuildHasher,
K: WeakElement,
<K as WeakElement>::Strong: Deref,
[src]
impl<'a, K, V, S> Index<&'a <K as WeakElement>::Strong> for PtrWeakKeyHashMap<K, V, S> where
S: BuildHasher,
K: WeakElement,
<K as WeakElement>::Strong: Deref,
[src]type Output = V
pub fn index(
&self,
index: &'a <K as WeakElement>::Strong
) -> &<PtrWeakKeyHashMap<K, V, S> as Index<&'a <K as WeakElement>::Strong>>::Output
[src]
&self,
index: &'a <K as WeakElement>::Strong
) -> &<PtrWeakKeyHashMap<K, V, S> as Index<&'a <K as WeakElement>::Strong>>::Output
impl<N> Index<usize> for Quaternion<N> where
N: SimdRealField,
[src]
impl<N> Index<usize> for Quaternion<N> where
N: SimdRealField,
[src]impl<N, R, C, S> Index<usize> for Matrix<N, R, C, S> where
C: Dim,
R: Dim,
S: Storage<N, R, C>,
N: Scalar,
[src]
impl<N, R, C, S> Index<usize> for Matrix<N, R, C, S> where
C: Dim,
R: Dim,
S: Storage<N, R, C>,
N: Scalar,
[src]impl<N, D> Index<usize> for Point<N, D> where
N: Scalar,
D: DimName,
DefaultAllocator: Allocator<N, D, U1>,
[src]
impl<N, D> Index<usize> for Point<N, D> where
N: Scalar,
D: DimName,
DefaultAllocator: Allocator<N, D, U1>,
[src]impl<N, D, C> Index<(usize, usize)> for Transform<N, D, C> where
C: TCategory,
N: RealField,
D: DimName + DimNameAdd<U1>,
DefaultAllocator: Allocator<N, <D as DimNameAdd<U1>>::Output, <D as DimNameAdd<U1>>::Output>,
[src]
impl<N, D, C> Index<(usize, usize)> for Transform<N, D, C> where
C: TCategory,
N: RealField,
D: DimName + DimNameAdd<U1>,
DefaultAllocator: Allocator<N, <D as DimNameAdd<U1>>::Output, <D as DimNameAdd<U1>>::Output>,
[src]impl<N, R, C, S> Index<(usize, usize)> for Matrix<N, R, C, S> where
C: Dim,
R: Dim,
S: Storage<N, R, C>,
N: Scalar,
[src]
impl<N, R, C, S> Index<(usize, usize)> for Matrix<N, R, C, S> where
C: Dim,
R: Dim,
S: Storage<N, R, C>,
N: Scalar,
[src]impl<N, D> Index<(usize, usize)> for Rotation<N, D> where
N: Scalar,
D: DimName,
DefaultAllocator: Allocator<N, D, D>,
[src]
impl<N, D> Index<(usize, usize)> for Rotation<N, D> where
N: Scalar,
D: DimName,
DefaultAllocator: Allocator<N, D, D>,
[src]Implementors
impl<'_, K, Q, V, S> Index<&'_ Q> for HashMap<K, V, S> where
S: BuildHasher,
K: Eq + Hash + Borrow<Q>,
Q: Eq + Hash + ?Sized,
[src]
impl<'_, K, Q, V, S> Index<&'_ Q> for HashMap<K, V, S> where
S: BuildHasher,
K: Eq + Hash + Borrow<Q>,
Q: Eq + Hash + ?Sized,
[src]