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