#[non_exhaustive]pub enum ApprovalStatus {
Approved,
Rejected,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against ApprovalStatus
, 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 approvalstatus = unimplemented!();
match approvalstatus {
ApprovalStatus::Approved => { /* ... */ },
ApprovalStatus::Rejected => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when approvalstatus
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant ApprovalStatus::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
ApprovalStatus::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 ApprovalStatus::NewFeature
is defined.
Specifically, when approvalstatus
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on ApprovalStatus::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
Approved
Rejected
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 ApprovalStatus
impl ApprovalStatus
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 ApprovalStatus
impl AsRef<str> for ApprovalStatus
source§impl Clone for ApprovalStatus
impl Clone for ApprovalStatus
source§fn clone(&self) -> ApprovalStatus
fn clone(&self) -> ApprovalStatus
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for ApprovalStatus
impl Debug for ApprovalStatus
source§impl Display for ApprovalStatus
impl Display for ApprovalStatus
source§impl From<&str> for ApprovalStatus
impl From<&str> for ApprovalStatus
source§impl FromStr for ApprovalStatus
impl FromStr for ApprovalStatus
source§impl Hash for ApprovalStatus
impl Hash for ApprovalStatus
source§impl Ord for ApprovalStatus
impl Ord for ApprovalStatus
source§fn cmp(&self, other: &ApprovalStatus) -> Ordering
fn cmp(&self, other: &ApprovalStatus) -> 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 ApprovalStatus
impl PartialEq for ApprovalStatus
source§impl PartialOrd for ApprovalStatus
impl PartialOrd for ApprovalStatus
impl Eq for ApprovalStatus
impl StructuralPartialEq for ApprovalStatus
Auto Trait Implementations§
impl Freeze for ApprovalStatus
impl RefUnwindSafe for ApprovalStatus
impl Send for ApprovalStatus
impl Sync for ApprovalStatus
impl Unpin for ApprovalStatus
impl UnwindSafe for ApprovalStatus
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.source§impl<T> Instrument for T
impl<T> Instrument for T
source§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
source§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
source§impl<T> IntoEither for T
impl<T> IntoEither for T
source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left
is true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moresource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left(&self)
returns true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read more