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