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