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