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