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