Struct ValueKey 

pub struct ValueKey<'a>(/* private fields */);

A key for looking up elements in Value arrays and maps.

ValueKey is the parameter type of Value::get, Value::get_mut, Value::remove, and the Index/IndexMut implementations on Value. You rarely name it directly: every type that implements Into<ValueKey> can be passed in, including:

• integers, floats, bool, SimpleValue, ()
• &str, &String
• &[u8]
• &Value
• &[Value], &Vec<Value>, &[Value; N], &Array (array-valued keys)
• &Map, &BTreeMap<Value, Value> (map-valued keys)

Lookups are zero-copy for the borrowed forms: passing &str, &[u8], &[Value], or &BTreeMap<Value, Value> does not allocate a full Value to compare against map keys.

Examples

use cbor_core::{Value, array, map};

let a = array![10, 20, 30];
assert_eq!(a[1].to_u32(), Ok(20));

let m = map! { "x" => 10, 2 => 20 };
assert_eq!(m["x"].to_u32(), Ok(10));
assert_eq!(m[2].to_u32(), Ok(20));

let k: [Value; _] = [1,2,3].map(Value::from);
let m = map! { k.clone() => "array as key" };
assert_eq!(m[&k].as_str(), Ok("array as key") );

let mut v = array![1, 2, 3];
v.remove(0);
assert_eq!(v.len(), Some(2));

Trait Implementations

impl<'a> Debug for ValueKey<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a, T, const N: usize> From<&'a [T; N]> for ValueKey<'a>

where ValueKey<'a>: From<&'a [T]>,

fn from(value: &'a [T; N]) -> Self

Converts to this type from the input type.

impl<'a> From<&'a [Value]> for ValueKey<'a>

fn from(value: &'a [Value]) -> Self

Converts to this type from the input type.

impl<'a> From<&'a [u8]> for ValueKey<'a>

fn from(value: &'a [u8]) -> Self

Converts to this type from the input type.

impl<'a> From<&'a Array> for ValueKey<'a>

fn from(value: &'a Array) -> Self

Converts to this type from the input type.

impl<'a> From<&'a BTreeMap<Value, Value>> for ValueKey<'a>

fn from(value: &'a BTreeMap<Value, Value>) -> Self

Converts to this type from the input type.

impl<'a> From<&'a Map> for ValueKey<'a>

fn from(value: &'a Map) -> Self

Converts to this type from the input type.

impl<'a> From<&'a String> for ValueKey<'a>

fn from(value: &'a String) -> Self

Converts to this type from the input type.

impl<'a> From<&'a Value> for ValueKey<'a>

fn from(value: &'a Value) -> Self

Converts to this type from the input type.

impl<'a, T> From<&'a Vec<T>> for ValueKey<'a>

where ValueKey<'a>: From<&'a [T]>,

fn from(value: &'a Vec<T>) -> Self

Converts to this type from the input type.

impl<'a> From<&'a str> for ValueKey<'a>

fn from(value: &'a str) -> Self

Converts to this type from the input type.

impl<'a> From<()> for ValueKey<'a>

fn from(value: ()) -> ValueKey<'a>

Converts to this type from the input type.

impl<'a> From<Float> for ValueKey<'a>

fn from(value: Float) -> ValueKey<'a>

Converts to this type from the input type.

impl<'a> From<SimpleValue> for ValueKey<'a>

fn from(value: SimpleValue) -> ValueKey<'a>

Converts to this type from the input type.

impl<'a> From<bool> for ValueKey<'a>

fn from(value: bool) -> ValueKey<'a>

Converts to this type from the input type.

impl From<f16> for ValueKey<'_>

Available on crate feature half only.

fn from(value: f16) -> Self

Converts to this type from the input type.

impl<'a> From<f32> for ValueKey<'a>

fn from(value: f32) -> ValueKey<'a>

Converts to this type from the input type.

impl<'a> From<f64> for ValueKey<'a>

fn from(value: f64) -> ValueKey<'a>

Converts to this type from the input type.

impl<'a> From<i128> for ValueKey<'a>

fn from(value: i128) -> ValueKey<'a>

Converts to this type from the input type.

impl<'a> From<i16> for ValueKey<'a>

fn from(value: i16) -> ValueKey<'a>

Converts to this type from the input type.

impl<'a> From<i32> for ValueKey<'a>

fn from(value: i32) -> ValueKey<'a>

Converts to this type from the input type.

impl<'a> From<i64> for ValueKey<'a>

fn from(value: i64) -> ValueKey<'a>

Converts to this type from the input type.

impl<'a> From<i8> for ValueKey<'a>

fn from(value: i8) -> ValueKey<'a>

Converts to this type from the input type.

impl<'a> From<isize> for ValueKey<'a>

fn from(value: isize) -> ValueKey<'a>

Converts to this type from the input type.

impl<'a> From<u128> for ValueKey<'a>

fn from(value: u128) -> ValueKey<'a>

Converts to this type from the input type.

impl<'a> From<u16> for ValueKey<'a>

fn from(value: u16) -> ValueKey<'a>

Converts to this type from the input type.

impl<'a> From<u32> for ValueKey<'a>

fn from(value: u32) -> ValueKey<'a>

Converts to this type from the input type.

impl<'a> From<u64> for ValueKey<'a>

fn from(value: u64) -> ValueKey<'a>

Converts to this type from the input type.

impl<'a> From<u8> for ValueKey<'a>

fn from(value: u8) -> ValueKey<'a>

Converts to this type from the input type.

impl<'a> From<usize> for ValueKey<'a>

fn from(value: usize) -> ValueKey<'a>

Converts to this type from the input type.