pub trait Index<Idx>where
Idx: ?Sized,{
type Output: ?Sized;
// Required method
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);Required Associated Types§
Required Methods§
Implementors§
§impl Index<usize> for FixedBitSet
Return true if the bit is enabled in the bitset,
or false otherwise.
impl Index<usize> for FixedBitSet
Return true if the bit is enabled in the bitset, or false otherwise.
Note: bits outside the capacity are always disabled, and thus indexing a FixedBitSet will not panic.
§impl Index<Range<usize>> for UninitSlice
impl Index<Range<usize>> for UninitSlice
type Output = UninitSlice
§impl Index<RangeFrom<usize>> for UninitSlice
impl Index<RangeFrom<usize>> for UninitSlice
type Output = UninitSlice
§impl Index<RangeFull> for UninitSlice
impl Index<RangeFull> for UninitSlice
type Output = UninitSlice
§impl Index<RangeInclusive<usize>> for UninitSlice
impl Index<RangeInclusive<usize>> for UninitSlice
type Output = UninitSlice
Source§impl Index<RangeInclusive<usize>> for ByteString
impl Index<RangeInclusive<usize>> for ByteString
§impl Index<RangeTo<usize>> for UninitSlice
impl Index<RangeTo<usize>> for UninitSlice
type Output = UninitSlice
§impl Index<RangeToInclusive<usize>> for UninitSlice
impl Index<RangeToInclusive<usize>> for UninitSlice
type Output = UninitSlice
Source§impl Index<RangeToInclusive<usize>> for ByteString
impl Index<RangeToInclusive<usize>> for ByteString
§impl<'h> Index<usize> for rama::utils::thirdparty::regex::bytes::Captures<'h>
Get a matching capture group’s haystack substring by index.
impl<'h> Index<usize> for rama::utils::thirdparty::regex::bytes::Captures<'h>
Get a matching capture group’s haystack substring by index.
The haystack substring returned can’t outlive the Captures object if this
method is used, because of how Index is defined (normally a[i] is part
of a and can’t outlive it). To work around this limitation, do that, use
Captures::get instead.
'h is the lifetime of the matched haystack, but the lifetime of the
&str returned by this implementation is the lifetime of the Captures
value itself.
§Panics
If there is no matching group at the given index.
§impl<'h> Index<usize> for rama::utils::thirdparty::regex::Captures<'h>
Get a matching capture group’s haystack substring by index.
impl<'h> Index<usize> for rama::utils::thirdparty::regex::Captures<'h>
Get a matching capture group’s haystack substring by index.
The haystack substring returned can’t outlive the Captures object if this
method is used, because of how Index is defined (normally a[i] is part
of a and can’t outlive it). To work around this limitation, do that, use
Captures::get instead.
'h is the lifetime of the matched haystack, but the lifetime of the
&str returned by this implementation is the lifetime of the Captures
value itself.
§Panics
If there is no matching group at the given index.
§impl<'h, 'n> Index<&'n str> for rama::utils::thirdparty::regex::bytes::Captures<'h>
Get a matching capture group’s haystack substring by name.
impl<'h, 'n> Index<&'n str> for rama::utils::thirdparty::regex::bytes::Captures<'h>
Get a matching capture group’s haystack substring by name.
The haystack substring returned can’t outlive the Captures object if this
method is used, because of how Index is defined (normally a[i] is part
of a and can’t outlive it). To work around this limitation, do that, use
Captures::name instead.
'h is the lifetime of the matched haystack, but the lifetime of the
&str returned by this implementation is the lifetime of the Captures
value itself.
'n is the lifetime of the group name used to index the Captures value.
§Panics
If there is no matching group at the given name.
§impl<'h, 'n> Index<&'n str> for rama::utils::thirdparty::regex::Captures<'h>
Get a matching capture group’s haystack substring by name.
impl<'h, 'n> Index<&'n str> for rama::utils::thirdparty::regex::Captures<'h>
Get a matching capture group’s haystack substring by name.
The haystack substring returned can’t outlive the Captures object if this
method is used, because of how Index is defined (normally a[i] is part
of a and can’t outlive it). To work around this limitation, do that, use
Captures::name instead.
'h is the lifetime of the matched haystack, but the lifetime of the
&str returned by this implementation is the lifetime of the Captures
value itself.
'n is the lifetime of the group name used to index the Captures value.
§Panics
If there is no matching group at the given name.
§impl<'s, T, I> Index<I> for SliceVec<'s, T>where
I: SliceIndex<[T]>,
impl<'s, T, I> Index<I> for SliceVec<'s, T>where
I: SliceIndex<[T]>,
type Output = <I as SliceIndex<[T]>>::Output
§impl<A, I> Index<I> for ArrayVec<A>where
A: Array,
I: SliceIndex<[<A as Array>::Item]>,
impl<A, I> Index<I> for ArrayVec<A>where
A: Array,
I: SliceIndex<[<A as Array>::Item]>,
type Output = <I as SliceIndex<[<A as Array>::Item]>>::Output
§impl<A, I> Index<I> for TinyVec<A>where
A: Array,
I: SliceIndex<[<A as Array>::Item]>,
impl<A, I> Index<I> for TinyVec<A>where
A: Array,
I: SliceIndex<[<A as Array>::Item]>,
type Output = <I as SliceIndex<[<A as Array>::Item]>>::Output
§impl<AllocU32> Index<BucketPopIndex> for EntropyBucketPopulation<AllocU32>where
AllocU32: Allocator<u32>,
impl<AllocU32> Index<BucketPopIndex> for EntropyBucketPopulation<AllocU32>where
AllocU32: Allocator<u32>,
1.0.0 · Source§impl<K, Q, V, S, A> Index<&Q> for rama::crypto::dep::x509_parser::prelude::asn1_rs::nom::lib::std::collections::HashMap<K, V, S, A>
impl<K, Q, V, S, A> Index<&Q> for rama::crypto::dep::x509_parser::prelude::asn1_rs::nom::lib::std::collections::HashMap<K, V, S, A>
§impl<K, V> Index<usize> for Keys<'_, K, V>
Access [IndexMap] keys at indexed positions.
impl<K, V> Index<usize> for Keys<'_, K, V>
Access [IndexMap] keys at indexed positions.
While Index<usize> for IndexMap accesses a map’s values,
indexing through [IndexMap::keys] offers an alternative to access a map’s
keys instead.
Since Keys is also an iterator, consuming items from the iterator will
offset the effective indices. Similarly, if Keys is obtained from
[Slice::keys], indices will be interpreted relative to the position of
that slice.
§Examples
use indexmap::IndexMap;
let mut map = IndexMap::new();
for word in "Lorem ipsum dolor sit amet".split_whitespace() {
map.insert(word.to_lowercase(), word.to_uppercase());
}
assert_eq!(map[0], "LOREM");
assert_eq!(map.keys()[0], "lorem");
assert_eq!(map[1], "IPSUM");
assert_eq!(map.keys()[1], "ipsum");
map.reverse();
assert_eq!(map.keys()[0], "amet");
assert_eq!(map.keys()[1], "sit");
map.sort_keys();
assert_eq!(map.keys()[0], "amet");
assert_eq!(map.keys()[1], "dolor");
// Advancing the iterator will offset the indexing
let mut keys = map.keys();
assert_eq!(keys[0], "amet");
assert_eq!(keys.next().map(|s| &**s), Some("amet"));
assert_eq!(keys[0], "dolor");
assert_eq!(keys[1], "ipsum");
// Slices may have an offset as well
let slice = &map[2..];
assert_eq!(slice[0], "IPSUM");
assert_eq!(slice.keys()[0], "ipsum");use indexmap::IndexMap;
let mut map = IndexMap::new();
map.insert("foo", 1);
println!("{:?}", map.keys()[10]); // panics!§impl<K, V, Q, S> Index<&Q> for IndexMap<K, V, S>
Access [IndexMap] values corresponding to a key.
impl<K, V, Q, S> Index<&Q> for IndexMap<K, V, S>
Access [IndexMap] values corresponding to a key.
§Examples
use indexmap::IndexMap;
let mut map = IndexMap::new();
for word in "Lorem ipsum dolor sit amet".split_whitespace() {
map.insert(word.to_lowercase(), word.to_uppercase());
}
assert_eq!(map["lorem"], "LOREM");
assert_eq!(map["ipsum"], "IPSUM");use indexmap::IndexMap;
let mut map = IndexMap::new();
map.insert("foo", 1);
println!("{:?}", map["bar"]); // panics!§impl<K, V, S> Index<usize> for IndexMap<K, V, S>
Access [IndexMap] values at indexed positions.
impl<K, V, S> Index<usize> for IndexMap<K, V, S>
Access [IndexMap] values at indexed positions.
See Index<usize> for Keys to access a map’s keys instead.
§Examples
use indexmap::IndexMap;
let mut map = IndexMap::new();
for word in "Lorem ipsum dolor sit amet".split_whitespace() {
map.insert(word.to_lowercase(), word.to_uppercase());
}
assert_eq!(map[0], "LOREM");
assert_eq!(map[1], "IPSUM");
map.reverse();
assert_eq!(map[0], "AMET");
assert_eq!(map[1], "SIT");
map.sort_keys();
assert_eq!(map[0], "AMET");
assert_eq!(map[1], "DOLOR");use indexmap::IndexMap;
let mut map = IndexMap::new();
map.insert("foo", 1);
println!("{:?}", map[10]); // panics!Source§impl<N, E, Ty, Ix> Index<EdgeIndex<Ix>> for Graph<N, E, Ty, Ix>
Index the Graph by EdgeIndex to access edge weights.
impl<N, E, Ty, Ix> Index<EdgeIndex<Ix>> for Graph<N, E, Ty, Ix>
Index the Graph by EdgeIndex to access edge weights.
Panics if the edge doesn’t exist.
Source§impl<N, E, Ty, Ix> Index<NodeIndex<Ix>> for Graph<N, E, Ty, Ix>
Index the Graph by NodeIndex to access node weights.
impl<N, E, Ty, Ix> Index<NodeIndex<Ix>> for Graph<N, E, Ty, Ix>
Index the Graph by NodeIndex to access node weights.
Panics if the node doesn’t exist.
Source§impl<Q> Index<&Q> for Map<String, Value>
Access an element of this map. Panics if the given key is not present in the
map.
impl<Q> Index<&Q> for Map<String, Value>
Access an element of this map. Panics if the given key is not present in the map.
match val {
Value::String(s) => Some(s.as_str()),
Value::Array(arr) => arr[0].as_str(),
Value::Object(map) => map["type"].as_str(),
_ => None,
}§impl<T> Index<PatternID> for rama::http::grpc::protobuf::prost::alloc::vec::Vec<T>
Available on crate feature alloc only.
impl<T> Index<PatternID> for rama::http::grpc::protobuf::prost::alloc::vec::Vec<T>
alloc only.§impl<T> Index<SmallIndex> for rama::http::grpc::protobuf::prost::alloc::vec::Vec<T>
Available on crate feature alloc only.
impl<T> Index<SmallIndex> for rama::http::grpc::protobuf::prost::alloc::vec::Vec<T>
alloc only.§impl<T> Index<StateID> for rama::http::grpc::protobuf::prost::alloc::vec::Vec<T>
Available on crate feature alloc only.
impl<T> Index<StateID> for rama::http::grpc::protobuf::prost::alloc::vec::Vec<T>
alloc only.§impl<T, I, A> Index<I> for Vec<T, A>where
I: SliceIndex<[T]>,
A: Allocator,
impl<T, I, A> Index<I> for Vec<T, A>where
I: SliceIndex<[T]>,
A: Allocator,
type Output = <I as SliceIndex<[T]>>::Output
§impl<T, S> Index<usize> for IndexSet<T, S>
Access [IndexSet] values at indexed positions.
impl<T, S> Index<usize> for IndexSet<T, S>
Access [IndexSet] values at indexed positions.
§Examples
use indexmap::IndexSet;
let mut set = IndexSet::new();
for word in "Lorem ipsum dolor sit amet".split_whitespace() {
set.insert(word.to_string());
}
assert_eq!(set[0], "Lorem");
assert_eq!(set[1], "ipsum");
set.reverse();
assert_eq!(set[0], "amet");
assert_eq!(set[1], "sit");
set.sort();
assert_eq!(set[0], "Lorem");
assert_eq!(set[1], "amet");use indexmap::IndexSet;
let mut set = IndexSet::new();
set.insert("foo");
println!("{:?}", set[10]); // panics!