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