#[non_exhaustive]
pub enum ResolutionStrategy {
Automerge,
Lambda,
None,
OptimisticConcurrency,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against ResolutionStrategy
, 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 resolutionstrategy = unimplemented!();
match resolutionstrategy {
ResolutionStrategy::Automerge => { /* ... */ },
ResolutionStrategy::Lambda => { /* ... */ },
ResolutionStrategy::None => { /* ... */ },
ResolutionStrategy::OptimisticConcurrency => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when resolutionstrategy
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant ResolutionStrategy::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
ResolutionStrategy::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 ResolutionStrategy::NewFeature
is defined.
Specifically, when resolutionstrategy
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on ResolutionStrategy::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
Automerge
Lambda
None
OptimisticConcurrency
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl AsRef<str> for ResolutionStrategy
impl AsRef<str> for ResolutionStrategy
source§impl Clone for ResolutionStrategy
impl Clone for ResolutionStrategy
source§fn clone(&self) -> ResolutionStrategy
fn clone(&self) -> ResolutionStrategy
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for ResolutionStrategy
impl Debug for ResolutionStrategy
source§impl From<&str> for ResolutionStrategy
impl From<&str> for ResolutionStrategy
source§impl FromStr for ResolutionStrategy
impl FromStr for ResolutionStrategy
source§impl Hash for ResolutionStrategy
impl Hash for ResolutionStrategy
source§impl Ord for ResolutionStrategy
impl Ord for ResolutionStrategy
source§fn cmp(&self, other: &ResolutionStrategy) -> Ordering
fn cmp(&self, other: &ResolutionStrategy) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
source§impl PartialEq<ResolutionStrategy> for ResolutionStrategy
impl PartialEq<ResolutionStrategy> for ResolutionStrategy
source§fn eq(&self, other: &ResolutionStrategy) -> bool
fn eq(&self, other: &ResolutionStrategy) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd<ResolutionStrategy> for ResolutionStrategy
impl PartialOrd<ResolutionStrategy> for ResolutionStrategy
source§fn partial_cmp(&self, other: &ResolutionStrategy) -> Option<Ordering>
fn partial_cmp(&self, other: &ResolutionStrategy) -> 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 ResolutionStrategy
impl StructuralEq for ResolutionStrategy
impl StructuralPartialEq for ResolutionStrategy
Auto Trait Implementations§
impl RefUnwindSafe for ResolutionStrategy
impl Send for ResolutionStrategy
impl Sync for ResolutionStrategy
impl Unpin for ResolutionStrategy
impl UnwindSafe for ResolutionStrategy
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.