Enum aws_sdk_waf::types::RateKey
source · #[non_exhaustive]pub enum RateKey {
Ip,
Unknown(UnknownVariantValue),
}Expand description
When writing a match expression against RateKey, 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 ratekey = unimplemented!();
match ratekey {
RateKey::Ip => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when ratekey represents
NewFeature, the execution path will lead to the second last match arm,
even though the enum does not contain a variant RateKey::NewFeature
in the current version of SDK. The reason is that the variable other,
created by the @ operator, is bound to
RateKey::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 RateKey::NewFeature is defined.
Specifically, when ratekey represents NewFeature,
the execution path will hit the second last match arm as before by virtue of
calling as_str on RateKey::NewFeature also yielding "NewFeature".
Explicitly matching on the Unknown variant should
be avoided for two reasons:
- The inner data
UnknownVariantValueis 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
Ip
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§
Trait Implementations§
source§impl Ord for RateKey
impl Ord for RateKey
source§impl PartialEq for RateKey
impl PartialEq for RateKey
source§impl PartialOrd for RateKey
impl PartialOrd for RateKey
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 RateKey
impl StructuralEq for RateKey
impl StructuralPartialEq for RateKey
Auto Trait Implementations§
impl RefUnwindSafe for RateKey
impl Send for RateKey
impl Sync for RateKey
impl Unpin for RateKey
impl UnwindSafe for RateKey
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.