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