#[non_exhaustive]pub enum ExportFormat {
DynamodbJson,
Ion,
Unknown(UnknownVariantValue),
}Expand description
When writing a match expression against ExportFormat, 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 exportformat = unimplemented!();
match exportformat {
ExportFormat::DynamodbJson => { /* ... */ },
ExportFormat::Ion => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}The above code demonstrates that when exportformat represents
NewFeature, the execution path will lead to the second last match arm,
even though the enum does not contain a variant ExportFormat::NewFeature
in the current version of SDK. The reason is that the variable other,
created by the @ operator, is bound to
ExportFormat::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 ExportFormat::NewFeature is defined.
Specifically, when exportformat represents NewFeature,
the execution path will hit the second last match arm as before by virtue of
calling as_str on ExportFormat::NewFeature also yielding "NewFeature".
Explicitly matching on the Unknown variant should
be avoided for two reasons:
- The inner data
UnknownVariantValueis 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
DynamodbJson
Ion
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 ExportFormat
impl ExportFormat
Source§impl ExportFormat
impl ExportFormat
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 ExportFormat
impl AsRef<str> for ExportFormat
Source§impl Clone for ExportFormat
impl Clone for ExportFormat
Source§fn clone(&self) -> ExportFormat
fn clone(&self) -> ExportFormat
1.0.0 · Source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source. Read moreSource§impl Debug for ExportFormat
impl Debug for ExportFormat
Source§impl Display for ExportFormat
impl Display for ExportFormat
Source§impl From<&str> for ExportFormat
impl From<&str> for ExportFormat
Source§impl FromStr for ExportFormat
impl FromStr for ExportFormat
Source§impl Hash for ExportFormat
impl Hash for ExportFormat
Source§impl Ord for ExportFormat
impl Ord for ExportFormat
Source§fn cmp(&self, other: &ExportFormat) -> Ordering
fn cmp(&self, other: &ExportFormat) -> 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 ExportFormat
impl PartialEq for ExportFormat
Source§impl PartialOrd for ExportFormat
impl PartialOrd for ExportFormat
impl Eq for ExportFormat
impl StructuralPartialEq for ExportFormat
Auto Trait Implementations§
impl Freeze for ExportFormat
impl RefUnwindSafe for ExportFormat
impl Send for ExportFormat
impl Sync for ExportFormat
impl Unpin for ExportFormat
impl UnwindSafe for ExportFormat
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<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
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§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