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