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