#[non_exhaustive]pub enum QueryPricingModel {
BytesScanned,
ComputeUnits,
Unknown(UnknownVariantValue),
}Expand description
When writing a match expression against QueryPricingModel, 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 querypricingmodel = unimplemented!();
match querypricingmodel {
QueryPricingModel::BytesScanned => { /* ... */ },
QueryPricingModel::ComputeUnits => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when querypricingmodel represents
NewFeature, the execution path will lead to the second last match arm,
even though the enum does not contain a variant QueryPricingModel::NewFeature
in the current version of SDK. The reason is that the variable other,
created by the @ operator, is bound to
QueryPricingModel::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 QueryPricingModel::NewFeature is defined.
Specifically, when querypricingmodel represents NewFeature,
the execution path will hit the second last match arm as before by virtue of
calling as_str on QueryPricingModel::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
BytesScanned
ComputeUnits
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 QueryPricingModel
impl QueryPricingModel
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 QueryPricingModel
impl AsRef<str> for QueryPricingModel
source§impl Clone for QueryPricingModel
impl Clone for QueryPricingModel
source§fn clone(&self) -> QueryPricingModel
fn clone(&self) -> QueryPricingModel
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source. Read moresource§impl Debug for QueryPricingModel
impl Debug for QueryPricingModel
source§impl Display for QueryPricingModel
impl Display for QueryPricingModel
source§impl From<&str> for QueryPricingModel
impl From<&str> for QueryPricingModel
source§impl FromStr for QueryPricingModel
impl FromStr for QueryPricingModel
source§impl Hash for QueryPricingModel
impl Hash for QueryPricingModel
source§impl Ord for QueryPricingModel
impl Ord for QueryPricingModel
source§fn cmp(&self, other: &QueryPricingModel) -> Ordering
fn cmp(&self, other: &QueryPricingModel) -> 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 QueryPricingModel
impl PartialEq for QueryPricingModel
source§fn eq(&self, other: &QueryPricingModel) -> bool
fn eq(&self, other: &QueryPricingModel) -> bool
self and other values to be equal, and is used
by ==.source§impl PartialOrd for QueryPricingModel
impl PartialOrd for QueryPricingModel
source§fn partial_cmp(&self, other: &QueryPricingModel) -> Option<Ordering>
fn partial_cmp(&self, other: &QueryPricingModel) -> 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 QueryPricingModel
impl StructuralPartialEq for QueryPricingModel
Auto Trait Implementations§
impl Freeze for QueryPricingModel
impl RefUnwindSafe for QueryPricingModel
impl Send for QueryPricingModel
impl Sync for QueryPricingModel
impl Unpin for QueryPricingModel
impl UnwindSafe for QueryPricingModel
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<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
source§default unsafe fn clone_to_uninit(&self, dst: *mut T)
default unsafe fn clone_to_uninit(&self, dst: *mut T)
clone_to_uninit)source§impl<Q, K> Comparable<K> for Q
impl<Q, K> Comparable<K> for Q
source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
source§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key and return true if they are equal.source§impl<T> Instrument for T
impl<T> Instrument for T
source§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
source§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
source§impl<T> IntoEither for T
impl<T> IntoEither for T
source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
self into a Left variant of Either<Self, Self>
if into_left is true.
Converts self into a Right variant of Either<Self, Self>
otherwise. Read moresource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
self into a Left variant of Either<Self, Self>
if into_left(&self) returns true.
Converts self into a Right variant of Either<Self, Self>
otherwise. Read more