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