Enum aws_sdk_ecs::types::TaskField
source · #[non_exhaustive]pub enum TaskField {
Tags,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against TaskField
, 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 taskfield = unimplemented!();
match taskfield {
TaskField::Tags => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when taskfield
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant TaskField::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
TaskField::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 TaskField::NewFeature
is defined.
Specifically, when taskfield
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on TaskField::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
Tags
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl Ord for TaskField
impl Ord for TaskField
source§impl PartialEq<TaskField> for TaskField
impl PartialEq<TaskField> for TaskField
source§impl PartialOrd<TaskField> for TaskField
impl PartialOrd<TaskField> for TaskField
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 TaskField
impl StructuralEq for TaskField
impl StructuralPartialEq for TaskField
Auto Trait Implementations§
impl RefUnwindSafe for TaskField
impl Send for TaskField
impl Sync for TaskField
impl Unpin for TaskField
impl UnwindSafe for TaskField
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.