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