Struct frame_support::storage::types::OptionQuery
source · pub struct OptionQuery;Expand description
Implement QueryKindTrait with query being Option<Value>
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
sourceimpl<Value> QueryKindTrait<Value, GetDefault> for OptionQuerywhere
Value: FullCodec + 'static,
impl<Value> QueryKindTrait<Value, GetDefault> for OptionQuerywhere
Value: FullCodec + 'static,
sourceconst METADATA: StorageEntryModifier = StorageEntryModifier::Optional
const METADATA: StorageEntryModifier = StorageEntryModifier::Optional
Metadata for the storage kind.
sourcefn 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. Read more
sourcefn 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 RefUnwindSafe for OptionQuery
impl Send for OptionQuery
impl Sync for OptionQuery
impl Unpin for OptionQuery
impl UnwindSafe for OptionQuery
Blanket Implementations
sourceimpl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
sourceimpl<T> CheckedConversion for T
impl<T> CheckedConversion for T
sourcefn checked_from<T>(t: T) -> Option<Self>where
Self: TryFrom<T>,
fn checked_from<T>(t: T) -> Option<Self>where
Self: TryFrom<T>,
sourcefn checked_into<T>(self) -> Option<T>where
Self: TryInto<T>,
fn checked_into<T>(self) -> Option<T>where
Self: TryInto<T>,
impl<T> Downcast for Twhere
T: Any,
impl<T> Downcast for Twhere
T: Any,
fn into_any(self: Box<T, Global>) -> Box<dyn Any + 'static, Global>
fn into_any(self: Box<T, Global>) -> Box<dyn Any + 'static, Global>
Convert
Box<dyn Trait> (where Trait: Downcast) to Box<dyn Any>. Box<dyn Any> can
then be further downcast into Box<ConcreteType> where ConcreteType implements Trait. Read morefn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>
fn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>
Convert
Rc<Trait> (where Trait: Downcast) to Rc<Any>. Rc<Any> can then be
further downcast into Rc<ConcreteType> where ConcreteType implements Trait. Read morefn as_any(&self) -> &(dyn Any + 'static)
fn as_any(&self) -> &(dyn Any + 'static)
Convert
&Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot
generate &Any’s vtable from &Trait’s. Read morefn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
Convert
&mut Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot
generate &mut Any’s vtable from &mut Trait’s. Read moresourceimpl<T> Instrument for T
impl<T> Instrument for T
sourcefn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
sourcefn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
sourceimpl<T, Outer> IsWrappedBy<Outer> for Twhere
Outer: AsRef<T> + AsMut<T> + From<T>,
T: From<Outer>,
impl<T, Outer> IsWrappedBy<Outer> for Twhere
Outer: AsRef<T> + AsMut<T> + From<T>,
T: From<Outer>,
impl<T> Pointable for T
impl<T> Pointable for T
sourceimpl<T> SaturatedConversion for T
impl<T> SaturatedConversion for T
sourcefn saturated_from<T>(t: T) -> Selfwhere
Self: UniqueSaturatedFrom<T>,
fn saturated_from<T>(t: T) -> Selfwhere
Self: UniqueSaturatedFrom<T>,
sourcefn 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 moresourceimpl<S, T> UncheckedInto<T> for Swhere
T: UncheckedFrom<S>,
impl<S, T> UncheckedInto<T> for Swhere
T: UncheckedFrom<S>,
sourcefn unchecked_into(self) -> T
fn unchecked_into(self) -> T
The counterpart to
unchecked_from.sourceimpl<T, S> UniqueSaturatedInto<T> for Swhere
T: Bounded,
S: TryInto<T>,
impl<T, S> UniqueSaturatedInto<T> for Swhere
T: Bounded,
S: TryInto<T>,
sourcefn unique_saturated_into(self) -> T
fn unique_saturated_into(self) -> T
Consume self to return an equivalent value of
T.