#[non_exhaustive]pub enum ExportDestinationType {
S3,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against ExportDestinationType
, 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 exportdestinationtype = unimplemented!();
match exportdestinationtype {
ExportDestinationType::S3 => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when exportdestinationtype
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant ExportDestinationType::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
ExportDestinationType::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 ExportDestinationType::NewFeature
is defined.
Specifically, when exportdestinationtype
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on ExportDestinationType::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
S3
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 ExportDestinationType
impl ExportDestinationType
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 ExportDestinationType
impl AsRef<str> for ExportDestinationType
source§impl Clone for ExportDestinationType
impl Clone for ExportDestinationType
source§fn clone(&self) -> ExportDestinationType
fn clone(&self) -> ExportDestinationType
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for ExportDestinationType
impl Debug for ExportDestinationType
source§impl From<&str> for ExportDestinationType
impl From<&str> for ExportDestinationType
source§impl FromStr for ExportDestinationType
impl FromStr for ExportDestinationType
source§impl Hash for ExportDestinationType
impl Hash for ExportDestinationType
source§impl Ord for ExportDestinationType
impl Ord for ExportDestinationType
source§fn cmp(&self, other: &ExportDestinationType) -> Ordering
fn cmp(&self, other: &ExportDestinationType) -> 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 ExportDestinationType
impl PartialEq for ExportDestinationType
source§fn eq(&self, other: &ExportDestinationType) -> bool
fn eq(&self, other: &ExportDestinationType) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd for ExportDestinationType
impl PartialOrd for ExportDestinationType
source§fn partial_cmp(&self, other: &ExportDestinationType) -> Option<Ordering>
fn partial_cmp(&self, other: &ExportDestinationType) -> 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 ExportDestinationType
impl StructuralEq for ExportDestinationType
impl StructuralPartialEq for ExportDestinationType
Auto Trait Implementations§
impl RefUnwindSafe for ExportDestinationType
impl Send for ExportDestinationType
impl Sync for ExportDestinationType
impl Unpin for ExportDestinationType
impl UnwindSafe for ExportDestinationType
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
§impl<Q, K> Equivalent<K> for Qwhere
Q: Eq + ?Sized,
K: Borrow<Q> + ?Sized,
impl<Q, K> Equivalent<K> for Qwhere Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,
§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
§impl<Q, K> Equivalent<K> for Qwhere
Q: Eq + ?Sized,
K: Borrow<Q> + ?Sized,
impl<Q, K> Equivalent<K> for Qwhere Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,
§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.