#[non_exhaustive]pub enum CloudWatchEventSource {
CodeDeploy,
Ec2,
Health,
Rds,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against CloudWatchEventSource
, 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 cloudwatcheventsource = unimplemented!();
match cloudwatcheventsource {
CloudWatchEventSource::CodeDeploy => { /* ... */ },
CloudWatchEventSource::Ec2 => { /* ... */ },
CloudWatchEventSource::Health => { /* ... */ },
CloudWatchEventSource::Rds => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when cloudwatcheventsource
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant CloudWatchEventSource::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
CloudWatchEventSource::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 CloudWatchEventSource::NewFeature
is defined.
Specifically, when cloudwatcheventsource
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on CloudWatchEventSource::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
CodeDeploy
Ec2
Health
Rds
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 CloudWatchEventSource
impl CloudWatchEventSource
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 CloudWatchEventSource
impl AsRef<str> for CloudWatchEventSource
source§impl Clone for CloudWatchEventSource
impl Clone for CloudWatchEventSource
source§fn clone(&self) -> CloudWatchEventSource
fn clone(&self) -> CloudWatchEventSource
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for CloudWatchEventSource
impl Debug for CloudWatchEventSource
source§impl Display for CloudWatchEventSource
impl Display for CloudWatchEventSource
source§impl From<&str> for CloudWatchEventSource
impl From<&str> for CloudWatchEventSource
source§impl FromStr for CloudWatchEventSource
impl FromStr for CloudWatchEventSource
source§impl Hash for CloudWatchEventSource
impl Hash for CloudWatchEventSource
source§impl Ord for CloudWatchEventSource
impl Ord for CloudWatchEventSource
source§fn cmp(&self, other: &CloudWatchEventSource) -> Ordering
fn cmp(&self, other: &CloudWatchEventSource) -> 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 CloudWatchEventSource
impl PartialEq for CloudWatchEventSource
source§fn eq(&self, other: &CloudWatchEventSource) -> bool
fn eq(&self, other: &CloudWatchEventSource) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd for CloudWatchEventSource
impl PartialOrd for CloudWatchEventSource
source§fn partial_cmp(&self, other: &CloudWatchEventSource) -> Option<Ordering>
fn partial_cmp(&self, other: &CloudWatchEventSource) -> 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 CloudWatchEventSource
impl StructuralPartialEq for CloudWatchEventSource
Auto Trait Implementations§
impl Freeze for CloudWatchEventSource
impl RefUnwindSafe for CloudWatchEventSource
impl Send for CloudWatchEventSource
impl Sync for CloudWatchEventSource
impl Unpin for CloudWatchEventSource
impl UnwindSafe for CloudWatchEventSource
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