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