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