Struct frame_support::storage::types::OptionQuery
source · pub struct OptionQuery;
Expand description
Implements QueryKindTrait
with Query
type being Option<_>
.
NOTE: it doesn’t support a generic OnEmpty
. This means only None
can be returned when no
value is found. To use another OnEmpty
implementation, ValueQuery
can be used instead.
Trait Implementations§
source§impl<Value> QueryKindTrait<Value, GetDefault> for OptionQuerywhere
Value: FullCodec + 'static,
impl<Value> QueryKindTrait<Value, GetDefault> for OptionQuerywhere
Value: FullCodec + 'static,
source§const METADATA: StorageEntryModifierIR = StorageEntryModifierIR::Optional
const METADATA: StorageEntryModifierIR = StorageEntryModifierIR::Optional
Metadata for the storage kind.
source§fn from_optional_value_to_query(v: Option<Value>) -> Self::Query
fn from_optional_value_to_query(v: Option<Value>) -> Self::Query
Convert an optional value (i.e. some if trie contains the value or none otherwise) to the
query.
source§fn from_query_to_optional_value(v: Self::Query) -> Option<Value>
fn from_query_to_optional_value(v: Self::Query) -> Option<Value>
Convert a query to an optional value.
Auto Trait Implementations§
impl Freeze for OptionQuery
impl RefUnwindSafe for OptionQuery
impl Send for OptionQuery
impl Sync for OptionQuery
impl Unpin for OptionQuery
impl UnwindSafe for OptionQuery
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
source§impl<T> CheckedConversion for T
impl<T> CheckedConversion for T
source§impl<T> Instrument for T
impl<T> Instrument for T
source§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
source§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
source§impl<T, Outer> IsWrappedBy<Outer> for T
impl<T, Outer> IsWrappedBy<Outer> for T
source§impl<T> SaturatedConversion for T
impl<T> SaturatedConversion for T
source§fn saturated_from<T>(t: T) -> Selfwhere
Self: UniqueSaturatedFrom<T>,
fn saturated_from<T>(t: T) -> Selfwhere
Self: UniqueSaturatedFrom<T>,
source§fn saturated_into<T>(self) -> Twhere
Self: UniqueSaturatedInto<T>,
fn saturated_into<T>(self) -> Twhere
Self: UniqueSaturatedInto<T>,
Consume self to return an equivalent value of
T
. Read moresource§impl<T, U> TryIntoKey<U> for Twhere
U: TryFromKey<T>,
impl<T, U> TryIntoKey<U> for Twhere
U: TryFromKey<T>,
type Error = <U as TryFromKey<T>>::Error
fn try_into_key(self) -> Result<U, <U as TryFromKey<T>>::Error>
source§impl<S, T> UncheckedInto<T> for Swhere
T: UncheckedFrom<S>,
impl<S, T> UncheckedInto<T> for Swhere
T: UncheckedFrom<S>,
source§fn unchecked_into(self) -> T
fn unchecked_into(self) -> T
The counterpart to
unchecked_from
.source§impl<T, S> UniqueSaturatedInto<T> for S
impl<T, S> UniqueSaturatedInto<T> for S
source§fn unique_saturated_into(self) -> T
fn unique_saturated_into(self) -> T
Consume self to return an equivalent value of
T
.