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