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