#[non_exhaustive]pub enum TransitionDefaultMinimumObjectSize {
AllStorageClasses128K,
VariesByStorageClass,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against TransitionDefaultMinimumObjectSize
, 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 transitiondefaultminimumobjectsize = unimplemented!();
match transitiondefaultminimumobjectsize {
TransitionDefaultMinimumObjectSize::AllStorageClasses128K => { /* ... */ },
TransitionDefaultMinimumObjectSize::VariesByStorageClass => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when transitiondefaultminimumobjectsize
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant TransitionDefaultMinimumObjectSize::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
TransitionDefaultMinimumObjectSize::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 TransitionDefaultMinimumObjectSize::NewFeature
is defined.
Specifically, when transitiondefaultminimumobjectsize
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on TransitionDefaultMinimumObjectSize::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
AllStorageClasses128K
VariesByStorageClass
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 TransitionDefaultMinimumObjectSize
impl TransitionDefaultMinimumObjectSize
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 Clone for TransitionDefaultMinimumObjectSize
impl Clone for TransitionDefaultMinimumObjectSize
source§fn clone(&self) -> TransitionDefaultMinimumObjectSize
fn clone(&self) -> TransitionDefaultMinimumObjectSize
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 TransitionDefaultMinimumObjectSize
impl From<&str> for TransitionDefaultMinimumObjectSize
source§impl Ord for TransitionDefaultMinimumObjectSize
impl Ord for TransitionDefaultMinimumObjectSize
source§fn cmp(&self, other: &TransitionDefaultMinimumObjectSize) -> Ordering
fn cmp(&self, other: &TransitionDefaultMinimumObjectSize) -> 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 TransitionDefaultMinimumObjectSize
impl PartialEq for TransitionDefaultMinimumObjectSize
source§fn eq(&self, other: &TransitionDefaultMinimumObjectSize) -> bool
fn eq(&self, other: &TransitionDefaultMinimumObjectSize) -> bool
self
and other
values to be equal, and is used by ==
.source§impl PartialOrd for TransitionDefaultMinimumObjectSize
impl PartialOrd for TransitionDefaultMinimumObjectSize
impl Eq for TransitionDefaultMinimumObjectSize
impl StructuralPartialEq for TransitionDefaultMinimumObjectSize
Auto Trait Implementations§
impl Freeze for TransitionDefaultMinimumObjectSize
impl RefUnwindSafe for TransitionDefaultMinimumObjectSize
impl Send for TransitionDefaultMinimumObjectSize
impl Sync for TransitionDefaultMinimumObjectSize
impl Unpin for TransitionDefaultMinimumObjectSize
impl UnwindSafe for TransitionDefaultMinimumObjectSize
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§unsafe fn clone_to_uninit(&self, dst: *mut T)
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§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.source§impl<T> Instrument for T
impl<T> Instrument for T
source§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
source§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
source§impl<T> IntoEither for T
impl<T> IntoEither for T
source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left
is true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moresource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left(&self)
returns true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read more