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