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