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