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