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