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