#[non_exhaustive]pub enum ApplicationStatus {
Deleting,
Ready,
Running,
Starting,
Stopping,
Updating,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against ApplicationStatus
, 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 applicationstatus = unimplemented!();
match applicationstatus {
ApplicationStatus::Deleting => { /* ... */ },
ApplicationStatus::Ready => { /* ... */ },
ApplicationStatus::Running => { /* ... */ },
ApplicationStatus::Starting => { /* ... */ },
ApplicationStatus::Stopping => { /* ... */ },
ApplicationStatus::Updating => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when applicationstatus
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant ApplicationStatus::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
ApplicationStatus::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 ApplicationStatus::NewFeature
is defined.
Specifically, when applicationstatus
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on ApplicationStatus::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
Deleting
Ready
Running
Starting
Stopping
Updating
Unknown(UnknownVariantValue)
Unknown
. See the docs on this enum for the correct way to handle unknown variants.Unknown
contains new variants that have been added since this code was generated.
Implementations§
source§impl ApplicationStatus
impl ApplicationStatus
sourcepub fn try_parse(value: &str) -> Result<Self, UnknownVariantError>
pub fn try_parse(value: &str) -> Result<Self, UnknownVariantError>
Parses the enum value while disallowing unknown variants.
Unknown variants will result in an error.
Trait Implementations§
source§impl AsRef<str> for ApplicationStatus
impl AsRef<str> for ApplicationStatus
source§impl Clone for ApplicationStatus
impl Clone for ApplicationStatus
source§fn clone(&self) -> ApplicationStatus
fn clone(&self) -> ApplicationStatus
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for ApplicationStatus
impl Debug for ApplicationStatus
source§impl Display for ApplicationStatus
impl Display for ApplicationStatus
source§impl From<&str> for ApplicationStatus
impl From<&str> for ApplicationStatus
source§impl FromStr for ApplicationStatus
impl FromStr for ApplicationStatus
source§impl Hash for ApplicationStatus
impl Hash for ApplicationStatus
source§impl Ord for ApplicationStatus
impl Ord for ApplicationStatus
source§fn cmp(&self, other: &ApplicationStatus) -> Ordering
fn cmp(&self, other: &ApplicationStatus) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
source§impl PartialEq for ApplicationStatus
impl PartialEq for ApplicationStatus
source§fn eq(&self, other: &ApplicationStatus) -> bool
fn eq(&self, other: &ApplicationStatus) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd for ApplicationStatus
impl PartialOrd for ApplicationStatus
source§fn partial_cmp(&self, other: &ApplicationStatus) -> Option<Ordering>
fn partial_cmp(&self, other: &ApplicationStatus) -> 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 ApplicationStatus
impl StructuralPartialEq for ApplicationStatus
Auto Trait Implementations§
impl Freeze for ApplicationStatus
impl RefUnwindSafe for ApplicationStatus
impl Send for ApplicationStatus
impl Sync for ApplicationStatus
impl Unpin for ApplicationStatus
impl UnwindSafe for ApplicationStatus
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> Comparable<K> for Q
impl<Q, K> Comparable<K> for Q
source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
source§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.source§impl<T> Instrument for T
impl<T> Instrument for T
source§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
source§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
source§impl<T> IntoEither for T
impl<T> IntoEither for T
source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left
is true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moresource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left(&self)
returns true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read more