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