#[non_exhaustive]pub enum CachePolicyHeaderBehavior {
None,
Whitelist,
Unknown(UnknownVariantValue),
}Expand description
When writing a match expression against CachePolicyHeaderBehavior, 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 cachepolicyheaderbehavior = unimplemented!();
match cachepolicyheaderbehavior {
CachePolicyHeaderBehavior::None => { /* ... */ },
CachePolicyHeaderBehavior::Whitelist => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when cachepolicyheaderbehavior represents
NewFeature, the execution path will lead to the second last match arm,
even though the enum does not contain a variant CachePolicyHeaderBehavior::NewFeature
in the current version of SDK. The reason is that the variable other,
created by the @ operator, is bound to
CachePolicyHeaderBehavior::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 CachePolicyHeaderBehavior::NewFeature is defined.
Specifically, when cachepolicyheaderbehavior represents NewFeature,
the execution path will hit the second last match arm as before by virtue of
calling as_str on CachePolicyHeaderBehavior::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
None
Whitelist
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 CachePolicyHeaderBehavior
impl CachePolicyHeaderBehavior
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 CachePolicyHeaderBehavior
impl AsRef<str> for CachePolicyHeaderBehavior
source§impl Clone for CachePolicyHeaderBehavior
impl Clone for CachePolicyHeaderBehavior
source§fn clone(&self) -> CachePolicyHeaderBehavior
fn clone(&self) -> CachePolicyHeaderBehavior
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source. Read moresource§impl Debug for CachePolicyHeaderBehavior
impl Debug for CachePolicyHeaderBehavior
source§impl From<&str> for CachePolicyHeaderBehavior
impl From<&str> for CachePolicyHeaderBehavior
source§impl FromStr for CachePolicyHeaderBehavior
impl FromStr for CachePolicyHeaderBehavior
source§impl Hash for CachePolicyHeaderBehavior
impl Hash for CachePolicyHeaderBehavior
source§impl Ord for CachePolicyHeaderBehavior
impl Ord for CachePolicyHeaderBehavior
source§fn cmp(&self, other: &CachePolicyHeaderBehavior) -> Ordering
fn cmp(&self, other: &CachePolicyHeaderBehavior) -> 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 CachePolicyHeaderBehavior
impl PartialEq for CachePolicyHeaderBehavior
source§fn eq(&self, other: &CachePolicyHeaderBehavior) -> bool
fn eq(&self, other: &CachePolicyHeaderBehavior) -> bool
self and other values to be equal, and is used
by ==.source§impl PartialOrd for CachePolicyHeaderBehavior
impl PartialOrd for CachePolicyHeaderBehavior
source§fn partial_cmp(&self, other: &CachePolicyHeaderBehavior) -> Option<Ordering>
fn partial_cmp(&self, other: &CachePolicyHeaderBehavior) -> 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 CachePolicyHeaderBehavior
impl StructuralEq for CachePolicyHeaderBehavior
impl StructuralPartialEq for CachePolicyHeaderBehavior
Auto Trait Implementations§
impl RefUnwindSafe for CachePolicyHeaderBehavior
impl Send for CachePolicyHeaderBehavior
impl Sync for CachePolicyHeaderBehavior
impl Unpin for CachePolicyHeaderBehavior
impl UnwindSafe for CachePolicyHeaderBehavior
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.