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