#[non_exhaustive]pub enum InstanceAutoRecoveryState {
Default,
Disabled,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against InstanceAutoRecoveryState
, 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 instanceautorecoverystate = unimplemented!();
match instanceautorecoverystate {
InstanceAutoRecoveryState::Default => { /* ... */ },
InstanceAutoRecoveryState::Disabled => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when instanceautorecoverystate
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant InstanceAutoRecoveryState::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
InstanceAutoRecoveryState::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 InstanceAutoRecoveryState::NewFeature
is defined.
Specifically, when instanceautorecoverystate
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on InstanceAutoRecoveryState::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
Default
Disabled
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl AsRef<str> for InstanceAutoRecoveryState
impl AsRef<str> for InstanceAutoRecoveryState
source§impl Clone for InstanceAutoRecoveryState
impl Clone for InstanceAutoRecoveryState
source§fn clone(&self) -> InstanceAutoRecoveryState
fn clone(&self) -> InstanceAutoRecoveryState
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for InstanceAutoRecoveryState
impl Debug for InstanceAutoRecoveryState
source§impl From<&str> for InstanceAutoRecoveryState
impl From<&str> for InstanceAutoRecoveryState
source§impl FromStr for InstanceAutoRecoveryState
impl FromStr for InstanceAutoRecoveryState
source§impl Hash for InstanceAutoRecoveryState
impl Hash for InstanceAutoRecoveryState
source§impl Ord for InstanceAutoRecoveryState
impl Ord for InstanceAutoRecoveryState
source§fn cmp(&self, other: &InstanceAutoRecoveryState) -> Ordering
fn cmp(&self, other: &InstanceAutoRecoveryState) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere Self: Sized,
source§impl PartialEq<InstanceAutoRecoveryState> for InstanceAutoRecoveryState
impl PartialEq<InstanceAutoRecoveryState> for InstanceAutoRecoveryState
source§fn eq(&self, other: &InstanceAutoRecoveryState) -> bool
fn eq(&self, other: &InstanceAutoRecoveryState) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd<InstanceAutoRecoveryState> for InstanceAutoRecoveryState
impl PartialOrd<InstanceAutoRecoveryState> for InstanceAutoRecoveryState
source§fn partial_cmp(&self, other: &InstanceAutoRecoveryState) -> Option<Ordering>
fn partial_cmp(&self, other: &InstanceAutoRecoveryState) -> 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 InstanceAutoRecoveryState
impl StructuralEq for InstanceAutoRecoveryState
impl StructuralPartialEq for InstanceAutoRecoveryState
Auto Trait Implementations§
impl RefUnwindSafe for InstanceAutoRecoveryState
impl Send for InstanceAutoRecoveryState
impl Sync for InstanceAutoRecoveryState
impl Unpin for InstanceAutoRecoveryState
impl UnwindSafe for InstanceAutoRecoveryState
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.