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