#[non_exhaustive]pub enum RegistrationStatus {
Deregistered,
Registered,
Unknown(UnknownVariantValue),
}Expand description
When writing a match expression against RegistrationStatus, 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 registrationstatus = unimplemented!();
match registrationstatus {
RegistrationStatus::Deregistered => { /* ... */ },
RegistrationStatus::Registered => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when registrationstatus represents
NewFeature, the execution path will lead to the second last match arm,
even though the enum does not contain a variant RegistrationStatus::NewFeature
in the current version of SDK. The reason is that the variable other,
created by the @ operator, is bound to
RegistrationStatus::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 RegistrationStatus::NewFeature is defined.
Specifically, when registrationstatus represents NewFeature,
the execution path will hit the second last match arm as before by virtue of
calling as_str on RegistrationStatus::NewFeature also yielding "NewFeature".
Explicitly matching on the Unknown variant should
be avoided for two reasons:
- The inner data
UnknownVariantValueis 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
Deregistered
Registered
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 RegistrationStatus
impl RegistrationStatus
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 RegistrationStatus
impl AsRef<str> for RegistrationStatus
source§impl Clone for RegistrationStatus
impl Clone for RegistrationStatus
source§fn clone(&self) -> RegistrationStatus
fn clone(&self) -> RegistrationStatus
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source. Read moresource§impl Debug for RegistrationStatus
impl Debug for RegistrationStatus
source§impl Display for RegistrationStatus
impl Display for RegistrationStatus
source§impl From<&str> for RegistrationStatus
impl From<&str> for RegistrationStatus
source§impl FromStr for RegistrationStatus
impl FromStr for RegistrationStatus
source§impl Hash for RegistrationStatus
impl Hash for RegistrationStatus
source§impl Ord for RegistrationStatus
impl Ord for RegistrationStatus
source§fn cmp(&self, other: &RegistrationStatus) -> Ordering
fn cmp(&self, other: &RegistrationStatus) -> 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 RegistrationStatus
impl PartialEq for RegistrationStatus
source§fn eq(&self, other: &RegistrationStatus) -> bool
fn eq(&self, other: &RegistrationStatus) -> bool
self and other values to be equal, and is used
by ==.source§impl PartialOrd for RegistrationStatus
impl PartialOrd for RegistrationStatus
source§fn partial_cmp(&self, other: &RegistrationStatus) -> Option<Ordering>
fn partial_cmp(&self, other: &RegistrationStatus) -> 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 RegistrationStatus
impl StructuralPartialEq for RegistrationStatus
Auto Trait Implementations§
impl Freeze for RegistrationStatus
impl RefUnwindSafe for RegistrationStatus
impl Send for RegistrationStatus
impl Sync for RegistrationStatus
impl Unpin for RegistrationStatus
impl UnwindSafe for RegistrationStatus
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