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