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