Struct frame_support::traits::StorageMapShim
source · pub struct StorageMapShim<S, K, T>(_);
Expand description
A shim for placing around a storage item in order to use it as a StoredValue
. Ideally this
wouldn’t be needed as StorageValue
s should blanket implement StoredValue
s, however this
would break the ability to have custom impls of StoredValue
. The other workaround is to
implement it directly in the macro.
This form has the advantage that two additional types are provides, Created
and Removed
,
which are both generic events that can be tied to handlers to do something in the case of being
about to create an account where one didn’t previously exist (at all; not just where it used to
be the default value), or where the account is being removed or reset back to the default value
where previously it did exist (though may have been in a default state). This works well with
system module’s CallOnCreatedAccount
and CallKillAccount
.
Trait Implementations
sourceimpl<S: StorageMap<K, T, Query = T>, K: FullCodec, T: FullCodec + Default> StoredMap<K, T> for StorageMapShim<S, K, T>
impl<S: StorageMap<K, T, Query = T>, K: FullCodec, T: FullCodec + Default> StoredMap<K, T> for StorageMapShim<S, K, T>
sourcefn get(k: &K) -> T
fn get(k: &K) -> T
sourcefn remove(k: &K) -> Result<(), DispatchError>
fn remove(k: &K) -> Result<(), DispatchError>
sourcefn mutate_exists<R>(
k: &K,
f: impl FnOnce(&mut Option<T>) -> R
) -> Result<R, DispatchError>
fn mutate_exists<R>(
k: &K,
f: impl FnOnce(&mut Option<T>) -> R
) -> Result<R, DispatchError>
None
. Read moresourcefn try_mutate_exists<R, E: From<DispatchError>>(
k: &K,
f: impl FnOnce(&mut Option<T>) -> Result<R, E>
) -> Result<R, E>
fn try_mutate_exists<R, E: From<DispatchError>>(
k: &K,
f: impl FnOnce(&mut Option<T>) -> Result<R, E>
) -> Result<R, E>
Ok
value is returned from f
. Do nothing if an Err
is
returned. It is removed or reset to default value if it has been mutated to None
.
f
will always be called with an option representing if the storage item exists (Some<V>
)
or if the storage item does not exist (None
), independent of the QueryType
. Read moreAuto Trait Implementations
impl<S, K, T> RefUnwindSafe for StorageMapShim<S, K, T>where
K: RefUnwindSafe,
S: RefUnwindSafe,
T: RefUnwindSafe,
impl<S, K, T> Send for StorageMapShim<S, K, T>where
K: Send,
S: Send,
T: Send,
impl<S, K, T> Sync for StorageMapShim<S, K, T>where
K: Sync,
S: Sync,
T: Sync,
impl<S, K, T> Unpin for StorageMapShim<S, K, T>where
K: Unpin,
S: Unpin,
T: Unpin,
impl<S, K, T> UnwindSafe for StorageMapShim<S, K, T>where
K: UnwindSafe,
S: UnwindSafe,
T: UnwindSafe,
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
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>
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>
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)
&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)
&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>,
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
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
T
.