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