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