#[non_exhaustive]pub enum RejectRuleBehavior {
All,
None,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against RejectRuleBehavior
, 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 rejectrulebehavior = unimplemented!();
match rejectrulebehavior {
RejectRuleBehavior::All => { /* ... */ },
RejectRuleBehavior::None => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when rejectrulebehavior
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant RejectRuleBehavior::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
RejectRuleBehavior::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 RejectRuleBehavior::NewFeature
is defined.
Specifically, when rejectrulebehavior
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on RejectRuleBehavior::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
All
None
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl AsRef<str> for RejectRuleBehavior
impl AsRef<str> for RejectRuleBehavior
source§impl Clone for RejectRuleBehavior
impl Clone for RejectRuleBehavior
source§fn clone(&self) -> RejectRuleBehavior
fn clone(&self) -> RejectRuleBehavior
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for RejectRuleBehavior
impl Debug for RejectRuleBehavior
source§impl From<&str> for RejectRuleBehavior
impl From<&str> for RejectRuleBehavior
source§impl FromStr for RejectRuleBehavior
impl FromStr for RejectRuleBehavior
source§impl Hash for RejectRuleBehavior
impl Hash for RejectRuleBehavior
source§impl Ord for RejectRuleBehavior
impl Ord for RejectRuleBehavior
source§fn cmp(&self, other: &RejectRuleBehavior) -> Ordering
fn cmp(&self, other: &RejectRuleBehavior) -> 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 RejectRuleBehavior
impl PartialEq for RejectRuleBehavior
source§fn eq(&self, other: &RejectRuleBehavior) -> bool
fn eq(&self, other: &RejectRuleBehavior) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd for RejectRuleBehavior
impl PartialOrd for RejectRuleBehavior
source§fn partial_cmp(&self, other: &RejectRuleBehavior) -> Option<Ordering>
fn partial_cmp(&self, other: &RejectRuleBehavior) -> 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 RejectRuleBehavior
impl StructuralEq for RejectRuleBehavior
impl StructuralPartialEq for RejectRuleBehavior
Auto Trait Implementations§
impl RefUnwindSafe for RejectRuleBehavior
impl Send for RejectRuleBehavior
impl Sync for RejectRuleBehavior
impl Unpin for RejectRuleBehavior
impl UnwindSafe for RejectRuleBehavior
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> Comparable<K> for Q
impl<Q, K> Comparable<K> for Q
§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.