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