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