Enum aws_sdk_batch::types::CeState
source · #[non_exhaustive]pub enum CeState {
Disabled,
Enabled,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against CeState
, 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 cestate = unimplemented!();
match cestate {
CeState::Disabled => { /* ... */ },
CeState::Enabled => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when cestate
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant CeState::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
CeState::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 CeState::NewFeature
is defined.
Specifically, when cestate
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on CeState::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
Disabled
Enabled
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl Ord for CeState
impl Ord for CeState
source§impl PartialEq<CeState> for CeState
impl PartialEq<CeState> for CeState
source§impl PartialOrd<CeState> for CeState
impl PartialOrd<CeState> for CeState
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 CeState
impl StructuralEq for CeState
impl StructuralPartialEq for CeState
Auto Trait Implementations§
impl RefUnwindSafe for CeState
impl Send for CeState
impl Sync for CeState
impl Unpin for CeState
impl UnwindSafe for CeState
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.