Struct serde_with::MapPreventDuplicates
source · pub struct MapPreventDuplicates<K, V>(/* private fields */);
Expand description
Ensure no duplicate keys exist in a map.
By default serde has a last-value-wins implementation, if duplicate keys for a map exist. Sometimes it is desirable to know when such an event happens, as the first value is overwritten and it can indicate an error in the serialized data.
This helper returns an error if two identical keys exist in a map.
The implementation supports both the HashMap
and the BTreeMap
from the standard library.
§Example
#[serde_as]
#[derive(Deserialize)]
struct Doc {
#[serde_as(as = "MapPreventDuplicates<_, _>")]
map: HashMap<usize, usize>,
}
// Maps are serialized normally,
let s = r#"{"map": {"1": 1, "2": 2, "3": 3}}"#;
let mut v = Doc {
map: HashMap::new(),
};
v.map.insert(1, 1);
v.map.insert(2, 2);
v.map.insert(3, 3);
assert_eq!(v, serde_json::from_str(s).unwrap());
// but create an error if duplicate keys, like the `1`, exist.
let s = r#"{"map": {"1": 1, "2": 2, "1": 3}}"#;
let res: Result<Doc, _> = serde_json::from_str(s);
assert!(res.is_err());
Trait Implementations§
source§impl<'de, K, V, KAs, VAs> DeserializeAs<'de, BTreeMap<K, V>> for MapPreventDuplicates<KAs, VAs>
impl<'de, K, V, KAs, VAs> DeserializeAs<'de, BTreeMap<K, V>> for MapPreventDuplicates<KAs, VAs>
source§fn deserialize_as<D>(deserializer: D) -> Result<BTreeMap<K, V>, D::Error>where
D: Deserializer<'de>,
fn deserialize_as<D>(deserializer: D) -> Result<BTreeMap<K, V>, D::Error>where
D: Deserializer<'de>,
Deserialize this value from the given Serde deserializer.
source§impl<'de, K, V, KAs, VAs, S> DeserializeAs<'de, HashMap<K, V, S>> for MapPreventDuplicates<KAs, VAs>where
KAs: DeserializeAs<'de, K>,
VAs: DeserializeAs<'de, V>,
K: Eq + Hash,
S: BuildHasher + Default,
impl<'de, K, V, KAs, VAs, S> DeserializeAs<'de, HashMap<K, V, S>> for MapPreventDuplicates<KAs, VAs>where
KAs: DeserializeAs<'de, K>,
VAs: DeserializeAs<'de, V>,
K: Eq + Hash,
S: BuildHasher + Default,
source§fn deserialize_as<D>(deserializer: D) -> Result<HashMap<K, V, S>, D::Error>where
D: Deserializer<'de>,
fn deserialize_as<D>(deserializer: D) -> Result<HashMap<K, V, S>, D::Error>where
D: Deserializer<'de>,
Deserialize this value from the given Serde deserializer.
source§impl<'de, K, V, KAs, VAs, S> DeserializeAs<'de, HashMap<K, V, S>> for MapPreventDuplicates<KAs, VAs>where
KAs: DeserializeAs<'de, K>,
VAs: DeserializeAs<'de, V>,
K: Eq + Hash,
S: BuildHasher + Default,
impl<'de, K, V, KAs, VAs, S> DeserializeAs<'de, HashMap<K, V, S>> for MapPreventDuplicates<KAs, VAs>where
KAs: DeserializeAs<'de, K>,
VAs: DeserializeAs<'de, V>,
K: Eq + Hash,
S: BuildHasher + Default,
source§fn deserialize_as<D>(
deserializer: D,
) -> Result<HashbrownMap014<K, V, S>, D::Error>where
D: Deserializer<'de>,
fn deserialize_as<D>(
deserializer: D,
) -> Result<HashbrownMap014<K, V, S>, D::Error>where
D: Deserializer<'de>,
Deserialize this value from the given Serde deserializer.
source§impl<'de, K, V, KAs, VAs, S> DeserializeAs<'de, IndexMap<K, V, S>> for MapPreventDuplicates<KAs, VAs>where
KAs: DeserializeAs<'de, K>,
VAs: DeserializeAs<'de, V>,
K: Eq + Hash,
S: BuildHasher + Default,
impl<'de, K, V, KAs, VAs, S> DeserializeAs<'de, IndexMap<K, V, S>> for MapPreventDuplicates<KAs, VAs>where
KAs: DeserializeAs<'de, K>,
VAs: DeserializeAs<'de, V>,
K: Eq + Hash,
S: BuildHasher + Default,
source§fn deserialize_as<D>(deserializer: D) -> Result<IndexMap<K, V, S>, D::Error>where
D: Deserializer<'de>,
fn deserialize_as<D>(deserializer: D) -> Result<IndexMap<K, V, S>, D::Error>where
D: Deserializer<'de>,
Deserialize this value from the given Serde deserializer.
source§impl<'de, K, V, KAs, VAs, S> DeserializeAs<'de, IndexMap<K, V, S>> for MapPreventDuplicates<KAs, VAs>where
KAs: DeserializeAs<'de, K>,
VAs: DeserializeAs<'de, V>,
K: Eq + Hash,
S: BuildHasher + Default,
impl<'de, K, V, KAs, VAs, S> DeserializeAs<'de, IndexMap<K, V, S>> for MapPreventDuplicates<KAs, VAs>where
KAs: DeserializeAs<'de, K>,
VAs: DeserializeAs<'de, V>,
K: Eq + Hash,
S: BuildHasher + Default,
source§fn deserialize_as<D>(deserializer: D) -> Result<IndexMap2<K, V, S>, D::Error>where
D: Deserializer<'de>,
fn deserialize_as<D>(deserializer: D) -> Result<IndexMap2<K, V, S>, D::Error>where
D: Deserializer<'de>,
Deserialize this value from the given Serde deserializer.
source§impl<K, V, KA, VA> JsonSchemaAs<BTreeMap<K, V>> for MapPreventDuplicates<KA, VA>where
VA: JsonSchemaAs<V>,
Available on crate feature schemars_0_8
only.
impl<K, V, KA, VA> JsonSchemaAs<BTreeMap<K, V>> for MapPreventDuplicates<KA, VA>where
VA: JsonSchemaAs<V>,
Available on crate feature
schemars_0_8
only.source§fn schema_name() -> String
fn schema_name() -> String
The name of the generated JSON Schema. Read more
source§fn schema_id() -> Cow<'static, str>
fn schema_id() -> Cow<'static, str>
Returns a string that uniquely identifies the schema produced by this type. Read more
source§fn json_schema(gen: &mut SchemaGenerator) -> Schema
fn json_schema(gen: &mut SchemaGenerator) -> Schema
Generates a JSON Schema for this type. Read more
source§fn is_referenceable() -> bool
fn is_referenceable() -> bool
Whether JSON Schemas generated for this type should be re-used where possible using the
$ref
keyword. Read moresource§impl<K, V, S, KA, VA> JsonSchemaAs<HashMap<K, V, S>> for MapPreventDuplicates<KA, VA>where
VA: JsonSchemaAs<V>,
Available on crate feature schemars_0_8
only.
impl<K, V, S, KA, VA> JsonSchemaAs<HashMap<K, V, S>> for MapPreventDuplicates<KA, VA>where
VA: JsonSchemaAs<V>,
Available on crate feature
schemars_0_8
only.source§fn schema_name() -> String
fn schema_name() -> String
The name of the generated JSON Schema. Read more
source§fn schema_id() -> Cow<'static, str>
fn schema_id() -> Cow<'static, str>
Returns a string that uniquely identifies the schema produced by this type. Read more
source§fn json_schema(gen: &mut SchemaGenerator) -> Schema
fn json_schema(gen: &mut SchemaGenerator) -> Schema
Generates a JSON Schema for this type. Read more
source§fn is_referenceable() -> bool
fn is_referenceable() -> bool
Whether JSON Schemas generated for this type should be re-used where possible using the
$ref
keyword. Read moresource§impl<K, V, S, KA, VA> JsonSchemaAs<HashMap<K, V, S>> for MapPreventDuplicates<KA, VA>where
VA: JsonSchemaAs<V>,
Available on crate feature schemars_0_8
only.
impl<K, V, S, KA, VA> JsonSchemaAs<HashMap<K, V, S>> for MapPreventDuplicates<KA, VA>where
VA: JsonSchemaAs<V>,
Available on crate feature
schemars_0_8
only.source§fn schema_name() -> String
fn schema_name() -> String
The name of the generated JSON Schema. Read more
source§fn schema_id() -> Cow<'static, str>
fn schema_id() -> Cow<'static, str>
Returns a string that uniquely identifies the schema produced by this type. Read more
source§fn json_schema(gen: &mut SchemaGenerator) -> Schema
fn json_schema(gen: &mut SchemaGenerator) -> Schema
Generates a JSON Schema for this type. Read more
source§fn is_referenceable() -> bool
fn is_referenceable() -> bool
Whether JSON Schemas generated for this type should be re-used where possible using the
$ref
keyword. Read moresource§impl<K, V, S, KA, VA> JsonSchemaAs<IndexMap<K, V, S>> for MapPreventDuplicates<KA, VA>where
VA: JsonSchemaAs<V>,
Available on crate feature schemars_0_8
only.
impl<K, V, S, KA, VA> JsonSchemaAs<IndexMap<K, V, S>> for MapPreventDuplicates<KA, VA>where
VA: JsonSchemaAs<V>,
Available on crate feature
schemars_0_8
only.source§fn schema_name() -> String
fn schema_name() -> String
The name of the generated JSON Schema. Read more
source§fn schema_id() -> Cow<'static, str>
fn schema_id() -> Cow<'static, str>
Returns a string that uniquely identifies the schema produced by this type. Read more
source§fn json_schema(gen: &mut SchemaGenerator) -> Schema
fn json_schema(gen: &mut SchemaGenerator) -> Schema
Generates a JSON Schema for this type. Read more
source§fn is_referenceable() -> bool
fn is_referenceable() -> bool
Whether JSON Schemas generated for this type should be re-used where possible using the
$ref
keyword. Read moresource§impl<K, V, S, KA, VA> JsonSchemaAs<IndexMap<K, V, S>> for MapPreventDuplicates<KA, VA>where
VA: JsonSchemaAs<V>,
Available on crate feature schemars_0_8
only.
impl<K, V, S, KA, VA> JsonSchemaAs<IndexMap<K, V, S>> for MapPreventDuplicates<KA, VA>where
VA: JsonSchemaAs<V>,
Available on crate feature
schemars_0_8
only.source§fn schema_name() -> String
fn schema_name() -> String
The name of the generated JSON Schema. Read more
source§fn schema_id() -> Cow<'static, str>
fn schema_id() -> Cow<'static, str>
Returns a string that uniquely identifies the schema produced by this type. Read more
source§fn json_schema(gen: &mut SchemaGenerator) -> Schema
fn json_schema(gen: &mut SchemaGenerator) -> Schema
Generates a JSON Schema for this type. Read more
source§fn is_referenceable() -> bool
fn is_referenceable() -> bool
Whether JSON Schemas generated for this type should be re-used where possible using the
$ref
keyword. Read moresource§impl<K, KAs, V, VAs> SerializeAs<BTreeMap<K, V>> for MapPreventDuplicates<KAs, VAs>where
KAs: SerializeAs<K>,
VAs: SerializeAs<V>,
impl<K, KAs, V, VAs> SerializeAs<BTreeMap<K, V>> for MapPreventDuplicates<KAs, VAs>where
KAs: SerializeAs<K>,
VAs: SerializeAs<V>,
source§fn serialize_as<S>(
value: &BTreeMap<K, V>,
serializer: S,
) -> Result<S::Ok, S::Error>where
S: Serializer,
fn serialize_as<S>(
value: &BTreeMap<K, V>,
serializer: S,
) -> Result<S::Ok, S::Error>where
S: Serializer,
Serialize this value into the given Serde serializer.
source§impl<K, KAs, V, VAs, H> SerializeAs<HashMap<K, V, H>> for MapPreventDuplicates<KAs, VAs>
impl<K, KAs, V, VAs, H> SerializeAs<HashMap<K, V, H>> for MapPreventDuplicates<KAs, VAs>
source§fn serialize_as<S>(
value: &HashMap<K, V, H>,
serializer: S,
) -> Result<S::Ok, S::Error>where
S: Serializer,
fn serialize_as<S>(
value: &HashMap<K, V, H>,
serializer: S,
) -> Result<S::Ok, S::Error>where
S: Serializer,
Serialize this value into the given Serde serializer.
source§impl<K, KAs, V, VAs, H> SerializeAs<HashMap<K, V, H>> for MapPreventDuplicates<KAs, VAs>
impl<K, KAs, V, VAs, H> SerializeAs<HashMap<K, V, H>> for MapPreventDuplicates<KAs, VAs>
source§fn serialize_as<S>(
value: &HashbrownMap014<K, V, H>,
serializer: S,
) -> Result<S::Ok, S::Error>where
S: Serializer,
fn serialize_as<S>(
value: &HashbrownMap014<K, V, H>,
serializer: S,
) -> Result<S::Ok, S::Error>where
S: Serializer,
Serialize this value into the given Serde serializer.
source§impl<K, KAs, V, VAs, H> SerializeAs<IndexMap<K, V, H>> for MapPreventDuplicates<KAs, VAs>
impl<K, KAs, V, VAs, H> SerializeAs<IndexMap<K, V, H>> for MapPreventDuplicates<KAs, VAs>
source§fn serialize_as<S>(
value: &IndexMap<K, V, H>,
serializer: S,
) -> Result<S::Ok, S::Error>where
S: Serializer,
fn serialize_as<S>(
value: &IndexMap<K, V, H>,
serializer: S,
) -> Result<S::Ok, S::Error>where
S: Serializer,
Serialize this value into the given Serde serializer.
source§impl<K, KAs, V, VAs, H> SerializeAs<IndexMap<K, V, H>> for MapPreventDuplicates<KAs, VAs>
impl<K, KAs, V, VAs, H> SerializeAs<IndexMap<K, V, H>> for MapPreventDuplicates<KAs, VAs>
source§fn serialize_as<S>(
value: &IndexMap2<K, V, H>,
serializer: S,
) -> Result<S::Ok, S::Error>where
S: Serializer,
fn serialize_as<S>(
value: &IndexMap2<K, V, H>,
serializer: S,
) -> Result<S::Ok, S::Error>where
S: Serializer,
Serialize this value into the given Serde serializer.
Auto Trait Implementations§
impl<K, V> Freeze for MapPreventDuplicates<K, V>
impl<K, V> RefUnwindSafe for MapPreventDuplicates<K, V>where
K: RefUnwindSafe,
V: RefUnwindSafe,
impl<K, V> Send for MapPreventDuplicates<K, V>
impl<K, V> Sync for MapPreventDuplicates<K, V>
impl<K, V> Unpin for MapPreventDuplicates<K, V>
impl<K, V> UnwindSafe for MapPreventDuplicates<K, V>where
K: UnwindSafe,
V: UnwindSafe,
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more