Enum aws_sdk_wafv2::types::FailureReason
source · #[non_exhaustive]pub enum FailureReason {
TokenDomainMismatch,
TokenExpired,
TokenInvalid,
TokenMissing,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against FailureReason
, 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 failurereason = unimplemented!();
match failurereason {
FailureReason::TokenDomainMismatch => { /* ... */ },
FailureReason::TokenExpired => { /* ... */ },
FailureReason::TokenInvalid => { /* ... */ },
FailureReason::TokenMissing => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when failurereason
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant FailureReason::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
FailureReason::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 FailureReason::NewFeature
is defined.
Specifically, when failurereason
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on FailureReason::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
TokenDomainMismatch
TokenExpired
TokenInvalid
TokenMissing
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 FailureReason
impl FailureReason
source§impl FailureReason
impl FailureReason
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 FailureReason
impl AsRef<str> for FailureReason
source§impl Clone for FailureReason
impl Clone for FailureReason
source§fn clone(&self) -> FailureReason
fn clone(&self) -> FailureReason
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for FailureReason
impl Debug for FailureReason
source§impl Display for FailureReason
impl Display for FailureReason
source§impl From<&str> for FailureReason
impl From<&str> for FailureReason
source§impl FromStr for FailureReason
impl FromStr for FailureReason
source§impl Hash for FailureReason
impl Hash for FailureReason
source§impl Ord for FailureReason
impl Ord for FailureReason
source§fn cmp(&self, other: &FailureReason) -> Ordering
fn cmp(&self, other: &FailureReason) -> 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 FailureReason
impl PartialEq for FailureReason
source§fn eq(&self, other: &FailureReason) -> bool
fn eq(&self, other: &FailureReason) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd for FailureReason
impl PartialOrd for FailureReason
source§fn partial_cmp(&self, other: &FailureReason) -> Option<Ordering>
fn partial_cmp(&self, other: &FailureReason) -> 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 FailureReason
impl StructuralPartialEq for FailureReason
Auto Trait Implementations§
impl Freeze for FailureReason
impl RefUnwindSafe for FailureReason
impl Send for FailureReason
impl Sync for FailureReason
impl Unpin for FailureReason
impl UnwindSafe for FailureReason
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.