Struct Map 

pub struct Map<K, V>(/* private fields */);

This serializes a list of tuples into a map

Normally, you want to use a HashMap or a BTreeMap when deserializing a map. However, sometimes this is not possible due to type constraints, e.g., if the type implements neither Hash nor Ord. Another use case is deserializing a map with duplicate keys.

Examples

Wrapper does not implement Hash nor Ord, thus prohibiting the use HashMap or BTreeMap. The JSON also contains a duplicate key.

#[serde_as]
#[derive(Debug, Deserialize, Serialize, Default)]
struct S {
    #[serde_as(as = "Map<_, _>")]
    s: Vec<(Wrapper<i32>, String)>,
}

#[derive(Clone, Debug, Serialize, Deserialize)]
#[serde(transparent)]
struct Wrapper<T>(T);

let data = S {
    s: vec![
        (Wrapper(1), "a".to_string()),
        (Wrapper(2), "b".to_string()),
        (Wrapper(3), "c".to_string()),
        (Wrapper(2), "d".to_string()),
    ],
};

let json = r#"{
  "s": {
    "1": "a",
    "2": "b",
    "3": "c",
    "2": "d"
  }
}"#;
assert_eq!(json, serde_json::to_string_pretty(&data).unwrap());

Trait Implementations

impl<'de, K, KAs, V, VAs, const N: usize> DeserializeAs<'de, [(K, V); N]> for Map<KAs, VAs>

where KAs: DeserializeAs<'de, K>, VAs: DeserializeAs<'de, V>,

fn deserialize_as<D>(deserializer: D) -> Result<[(K, V); N], D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<'de, K, KAs, V, VAs> DeserializeAs<'de, BTreeSet<(K, V)>> for Map<KAs, VAs>

where KAs: DeserializeAs<'de, K>, VAs: DeserializeAs<'de, V>, (K, V): Ord,

fn deserialize_as<D>(deserializer: D) -> Result<BTreeSet<(K, V)>, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<'de, K, KAs, V, VAs> DeserializeAs<'de, BinaryHeap<(K, V)>> for Map<KAs, VAs>

where KAs: DeserializeAs<'de, K>, VAs: DeserializeAs<'de, V>, (K, V): Ord,

fn deserialize_as<D>(deserializer: D) -> Result<BinaryHeap<(K, V)>, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<'de, K, KAs, V, VAs> DeserializeAs<'de, Box<[(K, V)]>> for Map<KAs, VAs>

where KAs: DeserializeAs<'de, K>, VAs: DeserializeAs<'de, V>, (K, V):,

fn deserialize_as<D>(deserializer: D) -> Result<Box<[(K, V)]>, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<'de, K, KAs, V, VAs, S> DeserializeAs<'de, HashSet<(K, V), S>> for Map<KAs, VAs>

where KAs: DeserializeAs<'de, K>, VAs: DeserializeAs<'de, V>, (K, V): Eq + Hash, S: BuildHasher + Default,

fn deserialize_as<D>(deserializer: D) -> Result<HashSet<(K, V), S>, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<'de, K, KAs, V, VAs> DeserializeAs<'de, LinkedList<(K, V)>> for Map<KAs, VAs>

where KAs: DeserializeAs<'de, K>, VAs: DeserializeAs<'de, V>, (K, V):,

fn deserialize_as<D>(deserializer: D) -> Result<LinkedList<(K, V)>, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<'de, K, KAs, V, VAs> DeserializeAs<'de, Vec<(K, V)>> for Map<KAs, VAs>

where KAs: DeserializeAs<'de, K>, VAs: DeserializeAs<'de, V>, (K, V):,

fn deserialize_as<D>(deserializer: D) -> Result<Vec<(K, V)>, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<'de, K, KAs, V, VAs> DeserializeAs<'de, VecDeque<(K, V)>> for Map<KAs, VAs>

where KAs: DeserializeAs<'de, K>, VAs: DeserializeAs<'de, V>, (K, V):,

fn deserialize_as<D>(deserializer: D) -> Result<VecDeque<(K, V)>, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<K, KAs, V, VAs> SerializeAs<[(K, V)]> for Map<KAs, VAs>

where KAs: SerializeAs<K>, VAs: SerializeAs<V>,

fn serialize_as<S>(source: &[(K, V)], serializer: S) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl<K, KAs, V, VAs, const N: usize> SerializeAs<[(K, V); N]> for Map<KAs, VAs>

where KAs: SerializeAs<K>, VAs: SerializeAs<V>,

fn serialize_as<S>( source: &[(K, V); N], serializer: S, ) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl<K, KAs, V, VAs> SerializeAs<BTreeSet<(K, V)>> for Map<KAs, VAs>

where KAs: SerializeAs<K>, VAs: SerializeAs<V>,

fn serialize_as<S>( source: &BTreeSet<(K, V)>, serializer: S, ) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl<K, KAs, V, VAs> SerializeAs<BinaryHeap<(K, V)>> for Map<KAs, VAs>

where KAs: SerializeAs<K>, VAs: SerializeAs<V>,

fn serialize_as<S>( source: &BinaryHeap<(K, V)>, serializer: S, ) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl<K, KAs, V, VAs> SerializeAs<Box<[(K, V)]>> for Map<KAs, VAs>

where KAs: SerializeAs<K>, VAs: SerializeAs<V>,

fn serialize_as<S>( source: &Box<[(K, V)]>, serializer: S, ) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl<K, KAs, V, VAs, H> SerializeAs<HashSet<(K, V), H>> for Map<KAs, VAs>

where KAs: SerializeAs<K>, VAs: SerializeAs<V>, H: ?Sized + Sized,

fn serialize_as<S>( source: &HashSet<(K, V), H>, serializer: S, ) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl<K, KAs, V, VAs> SerializeAs<LinkedList<(K, V)>> for Map<KAs, VAs>

where KAs: SerializeAs<K>, VAs: SerializeAs<V>,

fn serialize_as<S>( source: &LinkedList<(K, V)>, serializer: S, ) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl<K, KAs, V, VAs> SerializeAs<Option<(K, V)>> for Map<KAs, VAs>

where KAs: SerializeAs<K>, VAs: SerializeAs<V>,

fn serialize_as<S>( source: &Option<(K, V)>, serializer: S, ) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl<K, KAs, V, VAs> SerializeAs<Vec<(K, V)>> for Map<KAs, VAs>

where KAs: SerializeAs<K>, VAs: SerializeAs<V>,

fn serialize_as<S>( source: &Vec<(K, V)>, serializer: S, ) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl<K, KAs, V, VAs> SerializeAs<VecDeque<(K, V)>> for Map<KAs, VAs>

where KAs: SerializeAs<K>, VAs: SerializeAs<V>,

fn serialize_as<S>( source: &VecDeque<(K, V)>, serializer: S, ) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 0 bytes