#[non_exhaustive]
pub enum S3DataDistribution {
FullyReplicated,
ShardedByS3Key,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against S3DataDistribution
, 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 s3datadistribution = unimplemented!();
match s3datadistribution {
S3DataDistribution::FullyReplicated => { /* ... */ },
S3DataDistribution::ShardedByS3Key => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when s3datadistribution
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant S3DataDistribution::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
S3DataDistribution::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 S3DataDistribution::NewFeature
is defined.
Specifically, when s3datadistribution
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on S3DataDistribution::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
FullyReplicated
ShardedByS3Key
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl AsRef<str> for S3DataDistribution
impl AsRef<str> for S3DataDistribution
source§impl Clone for S3DataDistribution
impl Clone for S3DataDistribution
source§fn clone(&self) -> S3DataDistribution
fn clone(&self) -> S3DataDistribution
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for S3DataDistribution
impl Debug for S3DataDistribution
source§impl From<&str> for S3DataDistribution
impl From<&str> for S3DataDistribution
source§impl FromStr for S3DataDistribution
impl FromStr for S3DataDistribution
source§impl Hash for S3DataDistribution
impl Hash for S3DataDistribution
source§impl Ord for S3DataDistribution
impl Ord for S3DataDistribution
source§fn cmp(&self, other: &S3DataDistribution) -> Ordering
fn cmp(&self, other: &S3DataDistribution) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
source§impl PartialEq<S3DataDistribution> for S3DataDistribution
impl PartialEq<S3DataDistribution> for S3DataDistribution
source§fn eq(&self, other: &S3DataDistribution) -> bool
fn eq(&self, other: &S3DataDistribution) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd<S3DataDistribution> for S3DataDistribution
impl PartialOrd<S3DataDistribution> for S3DataDistribution
source§fn partial_cmp(&self, other: &S3DataDistribution) -> Option<Ordering>
fn partial_cmp(&self, other: &S3DataDistribution) -> 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 S3DataDistribution
impl StructuralEq for S3DataDistribution
impl StructuralPartialEq for S3DataDistribution
Auto Trait Implementations§
impl RefUnwindSafe for S3DataDistribution
impl Send for S3DataDistribution
impl Sync for S3DataDistribution
impl Unpin for S3DataDistribution
impl UnwindSafe for S3DataDistribution
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.