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