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