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