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