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