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