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