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