Enum aws_sdk_mq::types::PromoteMode
source · #[non_exhaustive]pub enum PromoteMode {
Failover,
Switchover,
Unknown(UnknownVariantValue),
}Expand description
When writing a match expression against PromoteMode, 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 promotemode = unimplemented!();
match promotemode {
PromoteMode::Failover => { /* ... */ },
PromoteMode::Switchover => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when promotemode represents
NewFeature, the execution path will lead to the second last match arm,
even though the enum does not contain a variant PromoteMode::NewFeature
in the current version of SDK. The reason is that the variable other,
created by the @ operator, is bound to
PromoteMode::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 PromoteMode::NewFeature is defined.
Specifically, when promotemode represents NewFeature,
the execution path will hit the second last match arm as before by virtue of
calling as_str on PromoteMode::NewFeature also yielding "NewFeature".
Explicitly matching on the Unknown variant should
be avoided for two reasons:
- The inner data
UnknownVariantValueis opaque, and no further information can be extracted. - It might inadvertently shadow other intended match arms.
The Promote mode requested.
Variants (Non-exhaustive)§
This enum is marked as non-exhaustive
Failover
Switchover
Unknown(UnknownVariantValue)
Unknown contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl AsRef<str> for PromoteMode
impl AsRef<str> for PromoteMode
source§impl Clone for PromoteMode
impl Clone for PromoteMode
source§fn clone(&self) -> PromoteMode
fn clone(&self) -> PromoteMode
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source. Read moresource§impl Debug for PromoteMode
impl Debug for PromoteMode
source§impl From<&str> for PromoteMode
impl From<&str> for PromoteMode
source§impl FromStr for PromoteMode
impl FromStr for PromoteMode
source§impl Hash for PromoteMode
impl Hash for PromoteMode
source§impl Ord for PromoteMode
impl Ord for PromoteMode
source§fn cmp(&self, other: &PromoteMode) -> Ordering
fn cmp(&self, other: &PromoteMode) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere Self: Sized,
source§impl PartialEq<PromoteMode> for PromoteMode
impl PartialEq<PromoteMode> for PromoteMode
source§fn eq(&self, other: &PromoteMode) -> bool
fn eq(&self, other: &PromoteMode) -> bool
self and other values to be equal, and is used
by ==.source§impl PartialOrd<PromoteMode> for PromoteMode
impl PartialOrd<PromoteMode> for PromoteMode
source§fn partial_cmp(&self, other: &PromoteMode) -> Option<Ordering>
fn partial_cmp(&self, other: &PromoteMode) -> 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 PromoteMode
impl StructuralEq for PromoteMode
impl StructuralPartialEq for PromoteMode
Auto Trait Implementations§
impl RefUnwindSafe for PromoteMode
impl Send for PromoteMode
impl Sync for PromoteMode
impl Unpin for PromoteMode
impl UnwindSafe for PromoteMode
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
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.