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