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