pub struct Impossible<Ok, Error> {
    void: Void,
    ok: PhantomData<Ok>,
    error: PhantomData<Error>,
}
Expand description

Helper type for implementing a Serializer that does not support serializing one of the compound types.

This type cannot be instantiated, but implements every one of the traits corresponding to the Serializer compound types: SerializeSeq, SerializeTuple, SerializeTupleStruct, SerializeTupleVariant, SerializeMap, SerializeStruct, and SerializeStructVariant.

impl Serializer for MySerializer {
    type Ok = ();
    type Error = Error;

    type SerializeSeq = Impossible<(), Error>;
    /* other associated types */

    /// This data format does not support serializing sequences.
    fn serialize_seq(self,
                     len: Option<usize>)
                     -> Result<Self::SerializeSeq, Error> {
        // Given Impossible cannot be instantiated, the only
        // thing we can do here is to return an error.
        Err(...)
    }

    /* other Serializer methods */
}

Fields

void: Voidok: PhantomData<Ok>error: PhantomData<Error>

Trait Implementations

Must match the Ok type of our Serializer.

Must match the Error type of our Serializer.

Serialize a map key. Read more

Serialize a map value. Read more

Finish serializing a map.

source

fn serialize_entry<K: ?Sized, V: ?Sized>(
    &mut self,
    key: &K,
    value: &V
) -> Result<(), Self::Error> where
    K: Serialize,
    V: Serialize

Serialize a map entry consisting of a key and a value. Read more

Must match the Ok type of our Serializer.

Must match the Error type of our Serializer.

Serialize a sequence element.

Finish serializing a sequence.

Must match the Ok type of our Serializer.

Must match the Error type of our Serializer.

Serialize a struct field.

Finish serializing a struct.

Indicate that a struct field has been skipped.

Must match the Ok type of our Serializer.

Must match the Error type of our Serializer.

Serialize a struct variant field.

Finish serializing a struct variant.

Indicate that a struct variant field has been skipped.

Must match the Ok type of our Serializer.

Must match the Error type of our Serializer.

Serialize a tuple element.

Finish serializing a tuple.

Must match the Ok type of our Serializer.

Must match the Error type of our Serializer.

Serialize a tuple struct field.

Finish serializing a tuple struct.

Must match the Ok type of our Serializer.

Must match the Error type of our Serializer.

Serialize a tuple variant field.

Finish serializing a tuple variant.

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.