#[non_exhaustive]
pub enum MetadataField {
AgentId,
AwsRequestId,
ComputePlatform,
ExecutionEnvironment,
LambdaFunctionArn,
LambdaMemoryLimitInMb,
LambdaPreviousExecutionTimeInMilliseconds,
LambdaRemainingTimeInMilliseconds,
LambdaTimeGapBetweenInvokesInMilliseconds,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against MetadataField
, 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 metadatafield = unimplemented!();
match metadatafield {
MetadataField::AgentId => { /* ... */ },
MetadataField::AwsRequestId => { /* ... */ },
MetadataField::ComputePlatform => { /* ... */ },
MetadataField::ExecutionEnvironment => { /* ... */ },
MetadataField::LambdaFunctionArn => { /* ... */ },
MetadataField::LambdaMemoryLimitInMb => { /* ... */ },
MetadataField::LambdaPreviousExecutionTimeInMilliseconds => { /* ... */ },
MetadataField::LambdaRemainingTimeInMilliseconds => { /* ... */ },
MetadataField::LambdaTimeGapBetweenInvokesInMilliseconds => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when metadatafield
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant MetadataField::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
MetadataField::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 MetadataField::NewFeature
is defined.
Specifically, when metadatafield
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on MetadataField::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
AgentId
Unique identifier for the agent instance.
AwsRequestId
AWS requestId of the Lambda invocation.
ComputePlatform
Compute platform on which agent is running.
ExecutionEnvironment
Execution environment on which Lambda function is running.
LambdaFunctionArn
Function ARN that’s used to invoke the Lambda function.
LambdaMemoryLimitInMb
Memory allocated for the Lambda function.
LambdaPreviousExecutionTimeInMilliseconds
Time in milliseconds for the previous Lambda invocation.
LambdaRemainingTimeInMilliseconds
Time in milliseconds left before the execution times out.
LambdaTimeGapBetweenInvokesInMilliseconds
Time in milliseconds between two invocations of the Lambda function.
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl AsRef<str> for MetadataField
impl AsRef<str> for MetadataField
source§impl Clone for MetadataField
impl Clone for MetadataField
source§fn clone(&self) -> MetadataField
fn clone(&self) -> MetadataField
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for MetadataField
impl Debug for MetadataField
source§impl From<&str> for MetadataField
impl From<&str> for MetadataField
source§impl FromStr for MetadataField
impl FromStr for MetadataField
source§impl Hash for MetadataField
impl Hash for MetadataField
source§impl Ord for MetadataField
impl Ord for MetadataField
source§fn cmp(&self, other: &MetadataField) -> Ordering
fn cmp(&self, other: &MetadataField) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
source§impl PartialEq<MetadataField> for MetadataField
impl PartialEq<MetadataField> for MetadataField
source§fn eq(&self, other: &MetadataField) -> bool
fn eq(&self, other: &MetadataField) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd<MetadataField> for MetadataField
impl PartialOrd<MetadataField> for MetadataField
source§fn partial_cmp(&self, other: &MetadataField) -> Option<Ordering>
fn partial_cmp(&self, other: &MetadataField) -> 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 MetadataField
impl StructuralEq for MetadataField
impl StructuralPartialEq for MetadataField
Auto Trait Implementations§
impl RefUnwindSafe for MetadataField
impl Send for MetadataField
impl Sync for MetadataField
impl Unpin for MetadataField
impl UnwindSafe for MetadataField
Blanket Implementations§
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.