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