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