#[non_exhaustive]pub enum StreamingSessionState {
CreateFailed,
CreateInProgress,
Deleted,
DeleteFailed,
DeleteInProgress,
Ready,
StartFailed,
StartInProgress,
Stopped,
StopFailed,
StopInProgress,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against StreamingSessionState
, 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 streamingsessionstate = unimplemented!();
match streamingsessionstate {
StreamingSessionState::CreateFailed => { /* ... */ },
StreamingSessionState::CreateInProgress => { /* ... */ },
StreamingSessionState::Deleted => { /* ... */ },
StreamingSessionState::DeleteFailed => { /* ... */ },
StreamingSessionState::DeleteInProgress => { /* ... */ },
StreamingSessionState::Ready => { /* ... */ },
StreamingSessionState::StartFailed => { /* ... */ },
StreamingSessionState::StartInProgress => { /* ... */ },
StreamingSessionState::Stopped => { /* ... */ },
StreamingSessionState::StopFailed => { /* ... */ },
StreamingSessionState::StopInProgress => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when streamingsessionstate
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant StreamingSessionState::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
StreamingSessionState::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 StreamingSessionState::NewFeature
is defined.
Specifically, when streamingsessionstate
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on StreamingSessionState::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.
The streaming session state.
Variants (Non-exhaustive)§
This enum is marked as non-exhaustive
CreateFailed
CreateInProgress
Deleted
DeleteFailed
DeleteInProgress
Ready
StartFailed
StartInProgress
Stopped
StopFailed
StopInProgress
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 StreamingSessionState
impl StreamingSessionState
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 StreamingSessionState
impl AsRef<str> for StreamingSessionState
source§impl Clone for StreamingSessionState
impl Clone for StreamingSessionState
source§fn clone(&self) -> StreamingSessionState
fn clone(&self) -> StreamingSessionState
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for StreamingSessionState
impl Debug for StreamingSessionState
source§impl From<&str> for StreamingSessionState
impl From<&str> for StreamingSessionState
source§impl FromStr for StreamingSessionState
impl FromStr for StreamingSessionState
source§impl Hash for StreamingSessionState
impl Hash for StreamingSessionState
source§impl Ord for StreamingSessionState
impl Ord for StreamingSessionState
source§fn cmp(&self, other: &StreamingSessionState) -> Ordering
fn cmp(&self, other: &StreamingSessionState) -> 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 StreamingSessionState
impl PartialEq for StreamingSessionState
source§fn eq(&self, other: &StreamingSessionState) -> bool
fn eq(&self, other: &StreamingSessionState) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd for StreamingSessionState
impl PartialOrd for StreamingSessionState
source§fn partial_cmp(&self, other: &StreamingSessionState) -> Option<Ordering>
fn partial_cmp(&self, other: &StreamingSessionState) -> 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 StreamingSessionState
impl StructuralEq for StreamingSessionState
impl StructuralPartialEq for StreamingSessionState
Auto Trait Implementations§
impl RefUnwindSafe for StreamingSessionState
impl Send for StreamingSessionState
impl Sync for StreamingSessionState
impl Unpin for StreamingSessionState
impl UnwindSafe for StreamingSessionState
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
§impl<Q, K> Comparable<K> for Q
impl<Q, K> Comparable<K> for Q
§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.