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