Enum aws_sdk_lightsail::types::AlarmState
source · #[non_exhaustive]pub enum AlarmState {
Alarm,
InsufficientData,
Ok,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against AlarmState
, 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 alarmstate = unimplemented!();
match alarmstate {
AlarmState::Alarm => { /* ... */ },
AlarmState::InsufficientData => { /* ... */ },
AlarmState::Ok => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when alarmstate
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant AlarmState::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
AlarmState::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 AlarmState::NewFeature
is defined.
Specifically, when alarmstate
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on AlarmState::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
Alarm
InsufficientData
Ok
Unknown(UnknownVariantValue)
Unknown
. See the docs on this enum for the correct way to handle unknown variants.Unknown
contains new variants that have been added since this code was generated.
Implementations§
source§impl AlarmState
impl AlarmState
source§impl AlarmState
impl AlarmState
sourcepub fn try_parse(value: &str) -> Result<Self, UnknownVariantError>
pub fn try_parse(value: &str) -> Result<Self, UnknownVariantError>
Parses the enum value while disallowing unknown variants.
Unknown variants will result in an error.
Trait Implementations§
source§impl AsRef<str> for AlarmState
impl AsRef<str> for AlarmState
source§impl Clone for AlarmState
impl Clone for AlarmState
source§fn clone(&self) -> AlarmState
fn clone(&self) -> AlarmState
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for AlarmState
impl Debug for AlarmState
source§impl Display for AlarmState
impl Display for AlarmState
source§impl From<&str> for AlarmState
impl From<&str> for AlarmState
source§impl FromStr for AlarmState
impl FromStr for AlarmState
source§impl Hash for AlarmState
impl Hash for AlarmState
source§impl Ord for AlarmState
impl Ord for AlarmState
source§fn cmp(&self, other: &AlarmState) -> Ordering
fn cmp(&self, other: &AlarmState) -> 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 AlarmState
impl PartialEq for AlarmState
source§fn eq(&self, other: &AlarmState) -> bool
fn eq(&self, other: &AlarmState) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd for AlarmState
impl PartialOrd for AlarmState
source§fn partial_cmp(&self, other: &AlarmState) -> Option<Ordering>
fn partial_cmp(&self, other: &AlarmState) -> 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 AlarmState
impl StructuralPartialEq for AlarmState
Auto Trait Implementations§
impl Freeze for AlarmState
impl RefUnwindSafe for AlarmState
impl Send for AlarmState
impl Sync for AlarmState
impl Unpin for AlarmState
impl UnwindSafe for AlarmState
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> Comparable<K> for Q
impl<Q, K> Comparable<K> for Q
source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
source§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.source§impl<T> Instrument for T
impl<T> Instrument for T
source§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
source§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
source§impl<T> IntoEither for T
impl<T> IntoEither for T
source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left
is true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moresource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left(&self)
returns true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read more