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Outdated,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StackInstanceStatus::Outdated =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Outdated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