#[non_exhaustive]pub enum EnabledOrDisabled {
Disabled,
Enabled,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against EnabledOrDisabled
, 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 enabledordisabled = unimplemented!();
match enabledordisabled {
EnabledOrDisabled::Disabled => { /* ... */ },
EnabledOrDisabled::Enabled => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when enabledordisabled
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant EnabledOrDisabled::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
EnabledOrDisabled::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 EnabledOrDisabled::NewFeature
is defined.
Specifically, when enabledordisabled
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on EnabledOrDisabled::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
. 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 EnabledOrDisabled
impl EnabledOrDisabled
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 EnabledOrDisabled
impl AsRef<str> for EnabledOrDisabled
source§impl Clone for EnabledOrDisabled
impl Clone for EnabledOrDisabled
source§fn clone(&self) -> EnabledOrDisabled
fn clone(&self) -> EnabledOrDisabled
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for EnabledOrDisabled
impl Debug for EnabledOrDisabled
source§impl Display for EnabledOrDisabled
impl Display for EnabledOrDisabled
source§impl From<&str> for EnabledOrDisabled
impl From<&str> for EnabledOrDisabled
source§impl FromStr for EnabledOrDisabled
impl FromStr for EnabledOrDisabled
source§impl Hash for EnabledOrDisabled
impl Hash for EnabledOrDisabled
source§impl Ord for EnabledOrDisabled
impl Ord for EnabledOrDisabled
source§fn cmp(&self, other: &EnabledOrDisabled) -> Ordering
fn cmp(&self, other: &EnabledOrDisabled) -> 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 EnabledOrDisabled
impl PartialEq for EnabledOrDisabled
source§impl PartialOrd for EnabledOrDisabled
impl PartialOrd for EnabledOrDisabled
impl Eq for EnabledOrDisabled
impl StructuralPartialEq for EnabledOrDisabled
Auto Trait Implementations§
impl Freeze for EnabledOrDisabled
impl RefUnwindSafe for EnabledOrDisabled
impl Send for EnabledOrDisabled
impl Sync for EnabledOrDisabled
impl Unpin for EnabledOrDisabled
impl UnwindSafe for EnabledOrDisabled
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<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
source§default unsafe fn clone_to_uninit(&self, dst: *mut T)
default unsafe fn clone_to_uninit(&self, dst: *mut T)
clone_to_uninit
)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