Enum aws_sdk_ec2::types::HostRecovery
source · #[non_exhaustive]pub enum HostRecovery {
Off,
On,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against HostRecovery
, 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 hostrecovery = unimplemented!();
match hostrecovery {
HostRecovery::Off => { /* ... */ },
HostRecovery::On => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when hostrecovery
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant HostRecovery::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
HostRecovery::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 HostRecovery::NewFeature
is defined.
Specifically, when hostrecovery
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on HostRecovery::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
Off
On
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl AsRef<str> for HostRecovery
impl AsRef<str> for HostRecovery
source§impl Clone for HostRecovery
impl Clone for HostRecovery
source§fn clone(&self) -> HostRecovery
fn clone(&self) -> HostRecovery
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for HostRecovery
impl Debug for HostRecovery
source§impl From<&str> for HostRecovery
impl From<&str> for HostRecovery
source§impl FromStr for HostRecovery
impl FromStr for HostRecovery
source§impl Hash for HostRecovery
impl Hash for HostRecovery
source§impl Ord for HostRecovery
impl Ord for HostRecovery
source§fn cmp(&self, other: &HostRecovery) -> Ordering
fn cmp(&self, other: &HostRecovery) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere Self: Sized,
source§impl PartialEq<HostRecovery> for HostRecovery
impl PartialEq<HostRecovery> for HostRecovery
source§fn eq(&self, other: &HostRecovery) -> bool
fn eq(&self, other: &HostRecovery) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd<HostRecovery> for HostRecovery
impl PartialOrd<HostRecovery> for HostRecovery
source§fn partial_cmp(&self, other: &HostRecovery) -> Option<Ordering>
fn partial_cmp(&self, other: &HostRecovery) -> 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 HostRecovery
impl StructuralEq for HostRecovery
impl StructuralPartialEq for HostRecovery
Auto Trait Implementations§
impl RefUnwindSafe for HostRecovery
impl Send for HostRecovery
impl Sync for HostRecovery
impl Unpin for HostRecovery
impl UnwindSafe for HostRecovery
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.