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