Enum aws_sdk_ec2::types::ImdsSupportValues
source · #[non_exhaustive]pub enum ImdsSupportValues {
V20,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against ImdsSupportValues
, 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 imdssupportvalues = unimplemented!();
match imdssupportvalues {
ImdsSupportValues::V20 => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when imdssupportvalues
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant ImdsSupportValues::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
ImdsSupportValues::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 ImdsSupportValues::NewFeature
is defined.
Specifically, when imdssupportvalues
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on ImdsSupportValues::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
V20
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl AsRef<str> for ImdsSupportValues
impl AsRef<str> for ImdsSupportValues
source§impl Clone for ImdsSupportValues
impl Clone for ImdsSupportValues
source§fn clone(&self) -> ImdsSupportValues
fn clone(&self) -> ImdsSupportValues
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for ImdsSupportValues
impl Debug for ImdsSupportValues
source§impl From<&str> for ImdsSupportValues
impl From<&str> for ImdsSupportValues
source§impl FromStr for ImdsSupportValues
impl FromStr for ImdsSupportValues
source§impl Hash for ImdsSupportValues
impl Hash for ImdsSupportValues
source§impl Ord for ImdsSupportValues
impl Ord for ImdsSupportValues
source§fn cmp(&self, other: &ImdsSupportValues) -> Ordering
fn cmp(&self, other: &ImdsSupportValues) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere Self: Sized,
source§impl PartialEq<ImdsSupportValues> for ImdsSupportValues
impl PartialEq<ImdsSupportValues> for ImdsSupportValues
source§fn eq(&self, other: &ImdsSupportValues) -> bool
fn eq(&self, other: &ImdsSupportValues) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd<ImdsSupportValues> for ImdsSupportValues
impl PartialOrd<ImdsSupportValues> for ImdsSupportValues
source§fn partial_cmp(&self, other: &ImdsSupportValues) -> Option<Ordering>
fn partial_cmp(&self, other: &ImdsSupportValues) -> 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 ImdsSupportValues
impl StructuralEq for ImdsSupportValues
impl StructuralPartialEq for ImdsSupportValues
Auto Trait Implementations§
impl RefUnwindSafe for ImdsSupportValues
impl Send for ImdsSupportValues
impl Sync for ImdsSupportValues
impl Unpin for ImdsSupportValues
impl UnwindSafe for ImdsSupportValues
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.