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