#[non_exhaustive]pub enum ReportInstanceReasonCodes {
InstanceStuckInState,
NotAcceptingCredentials,
Other,
PasswordNotAvailable,
PerformanceEbsVolume,
PerformanceInstanceStore,
PerformanceNetwork,
PerformanceOther,
Unresponsive,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against ReportInstanceReasonCodes
, 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 reportinstancereasoncodes = unimplemented!();
match reportinstancereasoncodes {
ReportInstanceReasonCodes::InstanceStuckInState => { /* ... */ },
ReportInstanceReasonCodes::NotAcceptingCredentials => { /* ... */ },
ReportInstanceReasonCodes::Other => { /* ... */ },
ReportInstanceReasonCodes::PasswordNotAvailable => { /* ... */ },
ReportInstanceReasonCodes::PerformanceEbsVolume => { /* ... */ },
ReportInstanceReasonCodes::PerformanceInstanceStore => { /* ... */ },
ReportInstanceReasonCodes::PerformanceNetwork => { /* ... */ },
ReportInstanceReasonCodes::PerformanceOther => { /* ... */ },
ReportInstanceReasonCodes::Unresponsive => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when reportinstancereasoncodes
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant ReportInstanceReasonCodes::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
ReportInstanceReasonCodes::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 ReportInstanceReasonCodes::NewFeature
is defined.
Specifically, when reportinstancereasoncodes
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on ReportInstanceReasonCodes::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
InstanceStuckInState
NotAcceptingCredentials
Other
PasswordNotAvailable
PerformanceEbsVolume
PerformanceInstanceStore
PerformanceNetwork
PerformanceOther
Unresponsive
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl AsRef<str> for ReportInstanceReasonCodes
impl AsRef<str> for ReportInstanceReasonCodes
source§impl Clone for ReportInstanceReasonCodes
impl Clone for ReportInstanceReasonCodes
source§fn clone(&self) -> ReportInstanceReasonCodes
fn clone(&self) -> ReportInstanceReasonCodes
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for ReportInstanceReasonCodes
impl Debug for ReportInstanceReasonCodes
source§impl From<&str> for ReportInstanceReasonCodes
impl From<&str> for ReportInstanceReasonCodes
source§impl FromStr for ReportInstanceReasonCodes
impl FromStr for ReportInstanceReasonCodes
source§impl Hash for ReportInstanceReasonCodes
impl Hash for ReportInstanceReasonCodes
source§impl Ord for ReportInstanceReasonCodes
impl Ord for ReportInstanceReasonCodes
source§fn cmp(&self, other: &ReportInstanceReasonCodes) -> Ordering
fn cmp(&self, other: &ReportInstanceReasonCodes) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere Self: Sized,
source§impl PartialEq<ReportInstanceReasonCodes> for ReportInstanceReasonCodes
impl PartialEq<ReportInstanceReasonCodes> for ReportInstanceReasonCodes
source§fn eq(&self, other: &ReportInstanceReasonCodes) -> bool
fn eq(&self, other: &ReportInstanceReasonCodes) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd<ReportInstanceReasonCodes> for ReportInstanceReasonCodes
impl PartialOrd<ReportInstanceReasonCodes> for ReportInstanceReasonCodes
source§fn partial_cmp(&self, other: &ReportInstanceReasonCodes) -> Option<Ordering>
fn partial_cmp(&self, other: &ReportInstanceReasonCodes) -> 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 ReportInstanceReasonCodes
impl StructuralEq for ReportInstanceReasonCodes
impl StructuralPartialEq for ReportInstanceReasonCodes
Auto Trait Implementations§
impl RefUnwindSafe for ReportInstanceReasonCodes
impl Send for ReportInstanceReasonCodes
impl Sync for ReportInstanceReasonCodes
impl Unpin for ReportInstanceReasonCodes
impl UnwindSafe for ReportInstanceReasonCodes
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> Equivalent<K> for Qwhere
Q: Eq + ?Sized,
K: Borrow<Q> + ?Sized,
impl<Q, K> Equivalent<K> for Qwhere Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,
source§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.