Enum aws_sdk_ec2::types::InstanceLifecycle
source · #[non_exhaustive]pub enum InstanceLifecycle {
OnDemand,
Spot,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against InstanceLifecycle
, 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 instancelifecycle = unimplemented!();
match instancelifecycle {
InstanceLifecycle::OnDemand => { /* ... */ },
InstanceLifecycle::Spot => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when instancelifecycle
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant InstanceLifecycle::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
InstanceLifecycle::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 InstanceLifecycle::NewFeature
is defined.
Specifically, when instancelifecycle
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on InstanceLifecycle::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
OnDemand
Spot
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl AsRef<str> for InstanceLifecycle
impl AsRef<str> for InstanceLifecycle
source§impl Clone for InstanceLifecycle
impl Clone for InstanceLifecycle
source§fn clone(&self) -> InstanceLifecycle
fn clone(&self) -> InstanceLifecycle
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for InstanceLifecycle
impl Debug for InstanceLifecycle
source§impl From<&str> for InstanceLifecycle
impl From<&str> for InstanceLifecycle
source§impl FromStr for InstanceLifecycle
impl FromStr for InstanceLifecycle
source§impl Hash for InstanceLifecycle
impl Hash for InstanceLifecycle
source§impl Ord for InstanceLifecycle
impl Ord for InstanceLifecycle
source§fn cmp(&self, other: &InstanceLifecycle) -> Ordering
fn cmp(&self, other: &InstanceLifecycle) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere Self: Sized,
source§impl PartialEq<InstanceLifecycle> for InstanceLifecycle
impl PartialEq<InstanceLifecycle> for InstanceLifecycle
source§fn eq(&self, other: &InstanceLifecycle) -> bool
fn eq(&self, other: &InstanceLifecycle) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd<InstanceLifecycle> for InstanceLifecycle
impl PartialOrd<InstanceLifecycle> for InstanceLifecycle
source§fn partial_cmp(&self, other: &InstanceLifecycle) -> Option<Ordering>
fn partial_cmp(&self, other: &InstanceLifecycle) -> 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 InstanceLifecycle
impl StructuralEq for InstanceLifecycle
impl StructuralPartialEq for InstanceLifecycle
Auto Trait Implementations§
impl RefUnwindSafe for InstanceLifecycle
impl Send for InstanceLifecycle
impl Sync for InstanceLifecycle
impl Unpin for InstanceLifecycle
impl UnwindSafe for InstanceLifecycle
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.