Enum aws_sdk_ssm::types::DocumentMetadataEnum
source · #[non_exhaustive]pub enum DocumentMetadataEnum {
DocumentReviews,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against DocumentMetadataEnum
, 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 documentmetadataenum = unimplemented!();
match documentmetadataenum {
DocumentMetadataEnum::DocumentReviews => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when documentmetadataenum
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant DocumentMetadataEnum::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
DocumentMetadataEnum::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 DocumentMetadataEnum::NewFeature
is defined.
Specifically, when documentmetadataenum
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on DocumentMetadataEnum::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
DocumentReviews
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§
source§impl DocumentMetadataEnum
impl DocumentMetadataEnum
sourcepub fn try_parse(value: &str) -> Result<Self, UnknownVariantError>
pub fn try_parse(value: &str) -> Result<Self, UnknownVariantError>
Parses the enum value while disallowing unknown variants.
Unknown variants will result in an error.
Trait Implementations§
source§impl AsRef<str> for DocumentMetadataEnum
impl AsRef<str> for DocumentMetadataEnum
source§impl Clone for DocumentMetadataEnum
impl Clone for DocumentMetadataEnum
source§fn clone(&self) -> DocumentMetadataEnum
fn clone(&self) -> DocumentMetadataEnum
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for DocumentMetadataEnum
impl Debug for DocumentMetadataEnum
source§impl Display for DocumentMetadataEnum
impl Display for DocumentMetadataEnum
source§impl From<&str> for DocumentMetadataEnum
impl From<&str> for DocumentMetadataEnum
source§impl FromStr for DocumentMetadataEnum
impl FromStr for DocumentMetadataEnum
source§impl Hash for DocumentMetadataEnum
impl Hash for DocumentMetadataEnum
source§impl Ord for DocumentMetadataEnum
impl Ord for DocumentMetadataEnum
source§fn cmp(&self, other: &DocumentMetadataEnum) -> Ordering
fn cmp(&self, other: &DocumentMetadataEnum) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
source§impl PartialEq for DocumentMetadataEnum
impl PartialEq for DocumentMetadataEnum
source§fn eq(&self, other: &DocumentMetadataEnum) -> bool
fn eq(&self, other: &DocumentMetadataEnum) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd for DocumentMetadataEnum
impl PartialOrd for DocumentMetadataEnum
source§fn partial_cmp(&self, other: &DocumentMetadataEnum) -> Option<Ordering>
fn partial_cmp(&self, other: &DocumentMetadataEnum) -> 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 DocumentMetadataEnum
impl StructuralPartialEq for DocumentMetadataEnum
Auto Trait Implementations§
impl Freeze for DocumentMetadataEnum
impl RefUnwindSafe for DocumentMetadataEnum
impl Send for DocumentMetadataEnum
impl Sync for DocumentMetadataEnum
impl Unpin for DocumentMetadataEnum
impl UnwindSafe for DocumentMetadataEnum
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> 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.