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