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