#[non_exhaustive]pub enum FastSnapshotRestoreStateCode {
Disabled,
Disabling,
Enabled,
Enabling,
Optimizing,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against FastSnapshotRestoreStateCode
, it is important to ensure
your code is forward-compatible. That is, if a match arm handles a case for a
feature that is supported by the service but has not been represented as an enum
variant in a current version of SDK, your code should continue to work when you
upgrade SDK to a future version in which the enum does include a variant for that
feature.
Here is an example of how you can make a match expression forward-compatible:
# let fastsnapshotrestorestatecode = unimplemented!();
match fastsnapshotrestorestatecode {
FastSnapshotRestoreStateCode::Disabled => { /* ... */ },
FastSnapshotRestoreStateCode::Disabling => { /* ... */ },
FastSnapshotRestoreStateCode::Enabled => { /* ... */ },
FastSnapshotRestoreStateCode::Enabling => { /* ... */ },
FastSnapshotRestoreStateCode::Optimizing => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when fastsnapshotrestorestatecode
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant FastSnapshotRestoreStateCode::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
FastSnapshotRestoreStateCode::Unknown(UnknownVariantValue("NewFeature".to_owned()))
and calling as_str
on it yields "NewFeature"
.
This match expression is forward-compatible when executed with a newer
version of SDK where the variant FastSnapshotRestoreStateCode::NewFeature
is defined.
Specifically, when fastsnapshotrestorestatecode
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on FastSnapshotRestoreStateCode::NewFeature
also yielding "NewFeature"
.
Explicitly matching on the Unknown
variant should
be avoided for two reasons:
- The inner data
UnknownVariantValue
is opaque, and no further information can be extracted. - It might inadvertently shadow other intended match arms.
Variants (Non-exhaustive)§
This enum is marked as non-exhaustive
Disabled
Disabling
Enabled
Enabling
Optimizing
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl AsRef<str> for FastSnapshotRestoreStateCode
impl AsRef<str> for FastSnapshotRestoreStateCode
source§impl Clone for FastSnapshotRestoreStateCode
impl Clone for FastSnapshotRestoreStateCode
source§fn clone(&self) -> FastSnapshotRestoreStateCode
fn clone(&self) -> FastSnapshotRestoreStateCode
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for FastSnapshotRestoreStateCode
impl Debug for FastSnapshotRestoreStateCode
source§impl From<&str> for FastSnapshotRestoreStateCode
impl From<&str> for FastSnapshotRestoreStateCode
source§impl Hash for FastSnapshotRestoreStateCode
impl Hash for FastSnapshotRestoreStateCode
source§impl Ord for FastSnapshotRestoreStateCode
impl Ord for FastSnapshotRestoreStateCode
source§fn cmp(&self, other: &FastSnapshotRestoreStateCode) -> Ordering
fn cmp(&self, other: &FastSnapshotRestoreStateCode) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere Self: Sized,
source§impl PartialEq<FastSnapshotRestoreStateCode> for FastSnapshotRestoreStateCode
impl PartialEq<FastSnapshotRestoreStateCode> for FastSnapshotRestoreStateCode
source§fn eq(&self, other: &FastSnapshotRestoreStateCode) -> bool
fn eq(&self, other: &FastSnapshotRestoreStateCode) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd<FastSnapshotRestoreStateCode> for FastSnapshotRestoreStateCode
impl PartialOrd<FastSnapshotRestoreStateCode> for FastSnapshotRestoreStateCode
source§fn partial_cmp(&self, other: &FastSnapshotRestoreStateCode) -> Option<Ordering>
fn partial_cmp(&self, other: &FastSnapshotRestoreStateCode) -> Option<Ordering>
1.0.0 · source§fn le(&self, other: &Rhs) -> bool
fn le(&self, other: &Rhs) -> bool
self
and other
) and is used by the <=
operator. Read moreimpl Eq for FastSnapshotRestoreStateCode
impl StructuralEq for FastSnapshotRestoreStateCode
impl StructuralPartialEq for FastSnapshotRestoreStateCode
Auto Trait Implementations§
impl RefUnwindSafe for FastSnapshotRestoreStateCode
impl Send for FastSnapshotRestoreStateCode
impl Sync for FastSnapshotRestoreStateCode
impl Unpin for FastSnapshotRestoreStateCode
impl UnwindSafe for FastSnapshotRestoreStateCode
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
source§impl<Q, K> Equivalent<K> for Qwhere
Q: Eq + ?Sized,
K: Borrow<Q> + ?Sized,
impl<Q, K> Equivalent<K> for Qwhere Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,
source§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.