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