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