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