#[non_exhaustive]pub enum ObjectVersionStorageClass {
Standard,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against ObjectVersionStorageClass
, 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 objectversionstorageclass = unimplemented!();
match objectversionstorageclass {
ObjectVersionStorageClass::Standard => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when objectversionstorageclass
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant ObjectVersionStorageClass::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
ObjectVersionStorageClass::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 ObjectVersionStorageClass::NewFeature
is defined.
Specifically, when objectversionstorageclass
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on ObjectVersionStorageClass::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
Standard
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 ObjectVersionStorageClass
impl ObjectVersionStorageClass
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 ObjectVersionStorageClass
impl AsRef<str> for ObjectVersionStorageClass
source§impl Clone for ObjectVersionStorageClass
impl Clone for ObjectVersionStorageClass
source§fn clone(&self) -> ObjectVersionStorageClass
fn clone(&self) -> ObjectVersionStorageClass
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for ObjectVersionStorageClass
impl Debug for ObjectVersionStorageClass
source§impl Display for ObjectVersionStorageClass
impl Display for ObjectVersionStorageClass
source§impl From<&str> for ObjectVersionStorageClass
impl From<&str> for ObjectVersionStorageClass
source§impl FromStr for ObjectVersionStorageClass
impl FromStr for ObjectVersionStorageClass
source§impl Hash for ObjectVersionStorageClass
impl Hash for ObjectVersionStorageClass
source§impl Ord for ObjectVersionStorageClass
impl Ord for ObjectVersionStorageClass
source§fn cmp(&self, other: &ObjectVersionStorageClass) -> Ordering
fn cmp(&self, other: &ObjectVersionStorageClass) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
source§impl PartialOrd for ObjectVersionStorageClass
impl PartialOrd for ObjectVersionStorageClass
impl Eq for ObjectVersionStorageClass
impl StructuralPartialEq for ObjectVersionStorageClass
Auto Trait Implementations§
impl Freeze for ObjectVersionStorageClass
impl RefUnwindSafe for ObjectVersionStorageClass
impl Send for ObjectVersionStorageClass
impl Sync for ObjectVersionStorageClass
impl Unpin for ObjectVersionStorageClass
impl UnwindSafe for ObjectVersionStorageClass
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<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
source§default unsafe fn clone_to_uninit(&self, dst: *mut T)
default unsafe fn clone_to_uninit(&self, dst: *mut T)
clone_to_uninit
)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.