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