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