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