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