Enum aws_sdk_emr::types::RepoUpgradeOnBoot
source · #[non_exhaustive]pub enum RepoUpgradeOnBoot {
None,
Security,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against RepoUpgradeOnBoot
, 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 repoupgradeonboot = unimplemented!();
match repoupgradeonboot {
RepoUpgradeOnBoot::None => { /* ... */ },
RepoUpgradeOnBoot::Security => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when repoupgradeonboot
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant RepoUpgradeOnBoot::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
RepoUpgradeOnBoot::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 RepoUpgradeOnBoot::NewFeature
is defined.
Specifically, when repoupgradeonboot
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on RepoUpgradeOnBoot::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
None
Security
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 RepoUpgradeOnBoot
impl RepoUpgradeOnBoot
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 RepoUpgradeOnBoot
impl AsRef<str> for RepoUpgradeOnBoot
source§impl Clone for RepoUpgradeOnBoot
impl Clone for RepoUpgradeOnBoot
source§fn clone(&self) -> RepoUpgradeOnBoot
fn clone(&self) -> RepoUpgradeOnBoot
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for RepoUpgradeOnBoot
impl Debug for RepoUpgradeOnBoot
source§impl From<&str> for RepoUpgradeOnBoot
impl From<&str> for RepoUpgradeOnBoot
source§impl FromStr for RepoUpgradeOnBoot
impl FromStr for RepoUpgradeOnBoot
source§impl Hash for RepoUpgradeOnBoot
impl Hash for RepoUpgradeOnBoot
source§impl Ord for RepoUpgradeOnBoot
impl Ord for RepoUpgradeOnBoot
source§fn cmp(&self, other: &RepoUpgradeOnBoot) -> Ordering
fn cmp(&self, other: &RepoUpgradeOnBoot) -> 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 RepoUpgradeOnBoot
impl PartialEq for RepoUpgradeOnBoot
source§fn eq(&self, other: &RepoUpgradeOnBoot) -> bool
fn eq(&self, other: &RepoUpgradeOnBoot) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd for RepoUpgradeOnBoot
impl PartialOrd for RepoUpgradeOnBoot
source§fn partial_cmp(&self, other: &RepoUpgradeOnBoot) -> Option<Ordering>
fn partial_cmp(&self, other: &RepoUpgradeOnBoot) -> 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 RepoUpgradeOnBoot
impl StructuralEq for RepoUpgradeOnBoot
impl StructuralPartialEq for RepoUpgradeOnBoot
Auto Trait Implementations§
impl RefUnwindSafe for RepoUpgradeOnBoot
impl Send for RepoUpgradeOnBoot
impl Sync for RepoUpgradeOnBoot
impl Unpin for RepoUpgradeOnBoot
impl UnwindSafe for RepoUpgradeOnBoot
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.