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