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