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
§impl<T> Conv for T
impl<T> Conv for T
§impl<T> FmtForward for T
impl<T> FmtForward for T
§fn fmt_binary(self) -> FmtBinary<Self>where
Self: Binary,
fn fmt_binary(self) -> FmtBinary<Self>where
Self: Binary,
Causes
self
to use its Binary
implementation when Debug
-formatted.§fn fmt_display(self) -> FmtDisplay<Self>where
Self: Display,
fn fmt_display(self) -> FmtDisplay<Self>where
Self: Display,
Causes
self
to use its Display
implementation when
Debug
-formatted.§fn fmt_lower_exp(self) -> FmtLowerExp<Self>where
Self: LowerExp,
fn fmt_lower_exp(self) -> FmtLowerExp<Self>where
Self: LowerExp,
Causes
self
to use its LowerExp
implementation when
Debug
-formatted.§fn fmt_lower_hex(self) -> FmtLowerHex<Self>where
Self: LowerHex,
fn fmt_lower_hex(self) -> FmtLowerHex<Self>where
Self: LowerHex,
Causes
self
to use its LowerHex
implementation when
Debug
-formatted.§fn fmt_octal(self) -> FmtOctal<Self>where
Self: Octal,
fn fmt_octal(self) -> FmtOctal<Self>where
Self: Octal,
Causes
self
to use its Octal
implementation when Debug
-formatted.§fn fmt_pointer(self) -> FmtPointer<Self>where
Self: Pointer,
fn fmt_pointer(self) -> FmtPointer<Self>where
Self: Pointer,
Causes
self
to use its Pointer
implementation when
Debug
-formatted.§fn fmt_upper_exp(self) -> FmtUpperExp<Self>where
Self: UpperExp,
fn fmt_upper_exp(self) -> FmtUpperExp<Self>where
Self: UpperExp,
Causes
self
to use its UpperExp
implementation when
Debug
-formatted.§fn fmt_upper_hex(self) -> FmtUpperHex<Self>where
Self: UpperHex,
fn fmt_upper_hex(self) -> FmtUpperHex<Self>where
Self: UpperHex,
Causes
self
to use its UpperHex
implementation when
Debug
-formatted.§fn fmt_list(self) -> FmtList<Self>where
&'a Self: for<'a> IntoIterator,
fn fmt_list(self) -> FmtList<Self>where
&'a Self: for<'a> IntoIterator,
Formats each item in a sequence. Read more
§impl<T> Instrument for T
impl<T> Instrument for T
§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
source§impl<T> IntoEither for T
impl<T> IntoEither for T
source§fn into_either(self, into_left: bool) -> Either<Self, Self> ⓘ
fn into_either(self, into_left: bool) -> Either<Self, Self> ⓘ
Converts
self
into a Left
variant of Either<Self, Self>
if into_left
is true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moresource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self> ⓘ
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self> ⓘ
Converts
self
into a Left
variant of Either<Self, Self>
if into_left(&self)
returns true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moresource§impl<T, Outer> IsWrappedBy<Outer> for T
impl<T, Outer> IsWrappedBy<Outer> for T
§impl<T> Pipe for Twhere
T: ?Sized,
impl<T> Pipe for Twhere
T: ?Sized,
§fn pipe<R>(self, func: impl FnOnce(Self) -> R) -> Rwhere
Self: Sized,
fn pipe<R>(self, func: impl FnOnce(Self) -> R) -> Rwhere
Self: Sized,
Pipes by value. This is generally the method you want to use. Read more
§fn pipe_ref<'a, R>(&'a self, func: impl FnOnce(&'a Self) -> R) -> Rwhere
R: 'a,
fn pipe_ref<'a, R>(&'a self, func: impl FnOnce(&'a Self) -> R) -> Rwhere
R: 'a,
Borrows
self
and passes that borrow into the pipe function. Read more§fn pipe_ref_mut<'a, R>(&'a mut self, func: impl FnOnce(&'a mut Self) -> R) -> Rwhere
R: 'a,
fn pipe_ref_mut<'a, R>(&'a mut self, func: impl FnOnce(&'a mut Self) -> R) -> Rwhere
R: 'a,
Mutably borrows
self
and passes that borrow into the pipe function. Read more§fn pipe_borrow<'a, B, R>(&'a self, func: impl FnOnce(&'a B) -> R) -> R
fn pipe_borrow<'a, B, R>(&'a self, func: impl FnOnce(&'a B) -> R) -> R
§fn pipe_borrow_mut<'a, B, R>(
&'a mut self,
func: impl FnOnce(&'a mut B) -> R,
) -> R
fn pipe_borrow_mut<'a, B, R>( &'a mut self, func: impl FnOnce(&'a mut B) -> R, ) -> R
§fn pipe_as_ref<'a, U, R>(&'a self, func: impl FnOnce(&'a U) -> R) -> R
fn pipe_as_ref<'a, U, R>(&'a self, func: impl FnOnce(&'a U) -> R) -> R
Borrows
self
, then passes self.as_ref()
into the pipe function.§fn pipe_as_mut<'a, U, R>(&'a mut self, func: impl FnOnce(&'a mut U) -> R) -> R
fn pipe_as_mut<'a, U, R>(&'a mut self, func: impl FnOnce(&'a mut U) -> R) -> R
Mutably borrows
self
, then passes self.as_mut()
into the pipe
function.§fn pipe_deref<'a, T, R>(&'a self, func: impl FnOnce(&'a T) -> R) -> R
fn pipe_deref<'a, T, R>(&'a self, func: impl FnOnce(&'a T) -> R) -> R
Borrows
self
, then passes self.deref()
into the pipe function.§impl<T> Pointable for T
impl<T> Pointable 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 more§impl<T> Tap for T
impl<T> Tap for T
§fn tap_borrow<B>(self, func: impl FnOnce(&B)) -> Self
fn tap_borrow<B>(self, func: impl FnOnce(&B)) -> Self
Immutable access to the
Borrow<B>
of a value. Read more§fn tap_borrow_mut<B>(self, func: impl FnOnce(&mut B)) -> Self
fn tap_borrow_mut<B>(self, func: impl FnOnce(&mut B)) -> Self
Mutable access to the
BorrowMut<B>
of a value. Read more§fn tap_ref<R>(self, func: impl FnOnce(&R)) -> Self
fn tap_ref<R>(self, func: impl FnOnce(&R)) -> Self
Immutable access to the
AsRef<R>
view of a value. Read more§fn tap_ref_mut<R>(self, func: impl FnOnce(&mut R)) -> Self
fn tap_ref_mut<R>(self, func: impl FnOnce(&mut R)) -> Self
Mutable access to the
AsMut<R>
view of a value. Read more§fn tap_deref<T>(self, func: impl FnOnce(&T)) -> Self
fn tap_deref<T>(self, func: impl FnOnce(&T)) -> Self
Immutable access to the
Deref::Target
of a value. Read more§fn tap_deref_mut<T>(self, func: impl FnOnce(&mut T)) -> Self
fn tap_deref_mut<T>(self, func: impl FnOnce(&mut T)) -> Self
Mutable access to the
Deref::Target
of a value. Read more§fn tap_dbg(self, func: impl FnOnce(&Self)) -> Self
fn tap_dbg(self, func: impl FnOnce(&Self)) -> Self
Calls
.tap()
only in debug builds, and is erased in release builds.§fn tap_mut_dbg(self, func: impl FnOnce(&mut Self)) -> Self
fn tap_mut_dbg(self, func: impl FnOnce(&mut Self)) -> Self
Calls
.tap_mut()
only in debug builds, and is erased in release
builds.§fn tap_borrow_dbg<B>(self, func: impl FnOnce(&B)) -> Self
fn tap_borrow_dbg<B>(self, func: impl FnOnce(&B)) -> Self
Calls
.tap_borrow()
only in debug builds, and is erased in release
builds.§fn tap_borrow_mut_dbg<B>(self, func: impl FnOnce(&mut B)) -> Self
fn tap_borrow_mut_dbg<B>(self, func: impl FnOnce(&mut B)) -> Self
Calls
.tap_borrow_mut()
only in debug builds, and is erased in release
builds.§fn tap_ref_dbg<R>(self, func: impl FnOnce(&R)) -> Self
fn tap_ref_dbg<R>(self, func: impl FnOnce(&R)) -> Self
Calls
.tap_ref()
only in debug builds, and is erased in release
builds.§fn tap_ref_mut_dbg<R>(self, func: impl FnOnce(&mut R)) -> Self
fn tap_ref_mut_dbg<R>(self, func: impl FnOnce(&mut R)) -> Self
Calls
.tap_ref_mut()
only in debug builds, and is erased in release
builds.§fn tap_deref_dbg<T>(self, func: impl FnOnce(&T)) -> Self
fn tap_deref_dbg<T>(self, func: impl FnOnce(&T)) -> Self
Calls
.tap_deref()
only in debug builds, and is erased in release
builds.§impl<T> TryConv for T
impl<T> TryConv for T
source§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
.