Enum aws_sdk_datasync::types::Uid
source · #[non_exhaustive]pub enum Uid {
Both,
IntValue,
Name,
None,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against Uid
, 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 uid = unimplemented!();
match uid {
Uid::Both => { /* ... */ },
Uid::IntValue => { /* ... */ },
Uid::Name => { /* ... */ },
Uid::None => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when uid
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant Uid::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
Uid::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 Uid::NewFeature
is defined.
Specifically, when uid
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on Uid::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
Both
IntValue
Name
None
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl Ord for Uid
impl Ord for Uid
source§impl PartialOrd<Uid> for Uid
impl PartialOrd<Uid> for Uid
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 Uid
impl StructuralEq for Uid
impl StructuralPartialEq for Uid
Auto Trait Implementations§
impl RefUnwindSafe for Uid
impl Send for Uid
impl Sync for Uid
impl Unpin for Uid
impl UnwindSafe for Uid
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.