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