#[non_exhaustive]pub enum CloudWatchMetricsStat {
Average,
Maximum,
Minimum,
SampleCount,
Sum,
P50,
P90,
P99,
Unknown(UnknownVariantValue),
}Expand description
When writing a match expression against CloudWatchMetricsStat, 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 cloudwatchmetricsstat = unimplemented!();
match cloudwatchmetricsstat {
CloudWatchMetricsStat::Average => { /* ... */ },
CloudWatchMetricsStat::Maximum => { /* ... */ },
CloudWatchMetricsStat::Minimum => { /* ... */ },
CloudWatchMetricsStat::SampleCount => { /* ... */ },
CloudWatchMetricsStat::Sum => { /* ... */ },
CloudWatchMetricsStat::P50 => { /* ... */ },
CloudWatchMetricsStat::P90 => { /* ... */ },
CloudWatchMetricsStat::P99 => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when cloudwatchmetricsstat represents
NewFeature, the execution path will lead to the second last match arm,
even though the enum does not contain a variant CloudWatchMetricsStat::NewFeature
in the current version of SDK. The reason is that the variable other,
created by the @ operator, is bound to
CloudWatchMetricsStat::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 CloudWatchMetricsStat::NewFeature is defined.
Specifically, when cloudwatchmetricsstat represents NewFeature,
the execution path will hit the second last match arm as before by virtue of
calling as_str on CloudWatchMetricsStat::NewFeature also yielding "NewFeature".
Explicitly matching on the Unknown variant should
be avoided for two reasons:
- The inner data
UnknownVariantValueis 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
Average
Maximum
Minimum
SampleCount
Sum
P50
P90
P99
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 CloudWatchMetricsStat
impl CloudWatchMetricsStat
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 CloudWatchMetricsStat
impl AsRef<str> for CloudWatchMetricsStat
source§impl Clone for CloudWatchMetricsStat
impl Clone for CloudWatchMetricsStat
source§fn clone(&self) -> CloudWatchMetricsStat
fn clone(&self) -> CloudWatchMetricsStat
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source. Read moresource§impl Debug for CloudWatchMetricsStat
impl Debug for CloudWatchMetricsStat
source§impl Display for CloudWatchMetricsStat
impl Display for CloudWatchMetricsStat
source§impl From<&str> for CloudWatchMetricsStat
impl From<&str> for CloudWatchMetricsStat
source§impl FromStr for CloudWatchMetricsStat
impl FromStr for CloudWatchMetricsStat
source§impl Hash for CloudWatchMetricsStat
impl Hash for CloudWatchMetricsStat
source§impl Ord for CloudWatchMetricsStat
impl Ord for CloudWatchMetricsStat
source§fn cmp(&self, other: &CloudWatchMetricsStat) -> Ordering
fn cmp(&self, other: &CloudWatchMetricsStat) -> 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 CloudWatchMetricsStat
impl PartialEq for CloudWatchMetricsStat
source§impl PartialOrd for CloudWatchMetricsStat
impl PartialOrd for CloudWatchMetricsStat
impl Eq for CloudWatchMetricsStat
impl StructuralPartialEq for CloudWatchMetricsStat
Auto Trait Implementations§
impl Freeze for CloudWatchMetricsStat
impl RefUnwindSafe for CloudWatchMetricsStat
impl Send for CloudWatchMetricsStat
impl Sync for CloudWatchMetricsStat
impl Unpin for CloudWatchMetricsStat
impl UnwindSafe for CloudWatchMetricsStat
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<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
source§unsafe fn clone_to_uninit(&self, dst: *mut T)
unsafe fn clone_to_uninit(&self, dst: *mut T)
clone_to_uninit)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