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