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