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