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