Trait scylla::deserialize::DeserializeValue
source · pub trait DeserializeValue<'frame, 'metadata>: Sized {
// Required methods
fn type_check(typ: &ColumnType<'_>) -> Result<(), TypeCheckError>;
fn deserialize(
typ: &'metadata ColumnType<'metadata>,
v: Option<FrameSlice<'frame>>,
) -> Result<Self, DeserializationError>;
}Expand description
A type that can be deserialized from a column value inside a row that was returned from a query.
For tips on how to write a custom implementation of this trait, see the documentation of the parent module.
The crate also provides a derive macro which allows to automatically implement the trait for a custom type. For more details on what the macro is capable of, see its documentation.
Required Methods§
sourcefn type_check(typ: &ColumnType<'_>) -> Result<(), TypeCheckError>
fn type_check(typ: &ColumnType<'_>) -> Result<(), TypeCheckError>
Checks that the column type matches what this type expects.
sourcefn deserialize(
typ: &'metadata ColumnType<'metadata>,
v: Option<FrameSlice<'frame>>,
) -> Result<Self, DeserializationError>
fn deserialize( typ: &'metadata ColumnType<'metadata>, v: Option<FrameSlice<'frame>>, ) -> Result<Self, DeserializationError>
Deserialize a column value from given serialized representation.
This function can assume that the driver called type_check to verify
the column’s type. Note that deserialize is not an unsafe function,
so it should not use the assumption about type_check being called
as an excuse to run unsafe code.
Object Safety§
This trait is not object safe.