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