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