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