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