Enum aws_sdk_ec2::model::PrefixListState
source · #[non_exhaustive]
pub enum PrefixListState {
Show 13 variants
CreateComplete,
CreateFailed,
CreateInProgress,
DeleteComplete,
DeleteFailed,
DeleteInProgress,
ModifyComplete,
ModifyFailed,
ModifyInProgress,
RestoreComplete,
RestoreFailed,
RestoreInProgress,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against PrefixListState
, 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 prefixliststate = unimplemented!();
match prefixliststate {
PrefixListState::CreateComplete => { /* ... */ },
PrefixListState::CreateFailed => { /* ... */ },
PrefixListState::CreateInProgress => { /* ... */ },
PrefixListState::DeleteComplete => { /* ... */ },
PrefixListState::DeleteFailed => { /* ... */ },
PrefixListState::DeleteInProgress => { /* ... */ },
PrefixListState::ModifyComplete => { /* ... */ },
PrefixListState::ModifyFailed => { /* ... */ },
PrefixListState::ModifyInProgress => { /* ... */ },
PrefixListState::RestoreComplete => { /* ... */ },
PrefixListState::RestoreFailed => { /* ... */ },
PrefixListState::RestoreInProgress => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when prefixliststate
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant PrefixListState::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
PrefixListState::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 PrefixListState::NewFeature
is defined.
Specifically, when prefixliststate
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on PrefixListState::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
CreateComplete
CreateFailed
CreateInProgress
DeleteComplete
DeleteFailed
DeleteInProgress
ModifyComplete
ModifyFailed
ModifyInProgress
RestoreComplete
RestoreFailed
RestoreInProgress
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl AsRef<str> for PrefixListState
impl AsRef<str> for PrefixListState
source§impl Clone for PrefixListState
impl Clone for PrefixListState
source§fn clone(&self) -> PrefixListState
fn clone(&self) -> PrefixListState
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for PrefixListState
impl Debug for PrefixListState
source§impl From<&str> for PrefixListState
impl From<&str> for PrefixListState
source§impl FromStr for PrefixListState
impl FromStr for PrefixListState
source§impl Hash for PrefixListState
impl Hash for PrefixListState
source§impl Ord for PrefixListState
impl Ord for PrefixListState
source§fn cmp(&self, other: &PrefixListState) -> Ordering
fn cmp(&self, other: &PrefixListState) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
source§impl PartialEq<PrefixListState> for PrefixListState
impl PartialEq<PrefixListState> for PrefixListState
source§fn eq(&self, other: &PrefixListState) -> bool
fn eq(&self, other: &PrefixListState) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd<PrefixListState> for PrefixListState
impl PartialOrd<PrefixListState> for PrefixListState
source§fn partial_cmp(&self, other: &PrefixListState) -> Option<Ordering>
fn partial_cmp(&self, other: &PrefixListState) -> 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 PrefixListState
impl StructuralEq for PrefixListState
impl StructuralPartialEq for PrefixListState
Auto Trait Implementations§
impl RefUnwindSafe for PrefixListState
impl Send for PrefixListState
impl Sync for PrefixListState
impl Unpin for PrefixListState
impl UnwindSafe for PrefixListState
Blanket Implementations§
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.