Enum aws_sdk_s3::types::JsonType
source · #[non_exhaustive]pub enum JsonType {
Document,
Lines,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against JsonType
, 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 jsontype = unimplemented!();
match jsontype {
JsonType::Document => { /* ... */ },
JsonType::Lines => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when jsontype
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant JsonType::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
JsonType::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 JsonType::NewFeature
is defined.
Specifically, when jsontype
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on JsonType::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
Document
Lines
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§
Trait Implementations§
source§impl Ord for JsonType
impl Ord for JsonType
source§impl PartialOrd for JsonType
impl PartialOrd for JsonType
impl Eq for JsonType
impl StructuralPartialEq for JsonType
Auto Trait Implementations§
impl Freeze for JsonType
impl RefUnwindSafe for JsonType
impl Send for JsonType
impl Sync for JsonType
impl Unpin for JsonType
impl UnwindSafe for JsonType
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<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
source§default unsafe fn clone_to_uninit(&self, dst: *mut T)
default unsafe fn clone_to_uninit(&self, dst: *mut T)
clone_to_uninit
)source§impl<Q, K> Comparable<K> for Q
impl<Q, K> Comparable<K> for Q
source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
source§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.