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