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