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