#[non_exhaustive]pub enum DirectConnectGatewayState {
Available,
Deleted,
Deleting,
Pending,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against DirectConnectGatewayState
, 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 directconnectgatewaystate = unimplemented!();
match directconnectgatewaystate {
DirectConnectGatewayState::Available => { /* ... */ },
DirectConnectGatewayState::Deleted => { /* ... */ },
DirectConnectGatewayState::Deleting => { /* ... */ },
DirectConnectGatewayState::Pending => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when directconnectgatewaystate
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant DirectConnectGatewayState::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
DirectConnectGatewayState::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 DirectConnectGatewayState::NewFeature
is defined.
Specifically, when directconnectgatewaystate
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on DirectConnectGatewayState::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
Deleted
Deleting
Pending
Unknown(UnknownVariantValue)
Unknown
. See the docs on this enum for the correct way to handle unknown variants.Unknown
contains new variants that have been added since this code was generated.
Implementations§
source§impl DirectConnectGatewayState
impl DirectConnectGatewayState
sourcepub fn try_parse(value: &str) -> Result<Self, UnknownVariantError>
pub fn try_parse(value: &str) -> Result<Self, UnknownVariantError>
Parses the enum value while disallowing unknown variants.
Unknown variants will result in an error.
Trait Implementations§
source§impl AsRef<str> for DirectConnectGatewayState
impl AsRef<str> for DirectConnectGatewayState
source§impl Clone for DirectConnectGatewayState
impl Clone for DirectConnectGatewayState
source§fn clone(&self) -> DirectConnectGatewayState
fn clone(&self) -> DirectConnectGatewayState
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for DirectConnectGatewayState
impl Debug for DirectConnectGatewayState
source§impl From<&str> for DirectConnectGatewayState
impl From<&str> for DirectConnectGatewayState
source§impl FromStr for DirectConnectGatewayState
impl FromStr for DirectConnectGatewayState
source§impl Hash for DirectConnectGatewayState
impl Hash for DirectConnectGatewayState
source§impl Ord for DirectConnectGatewayState
impl Ord for DirectConnectGatewayState
source§fn cmp(&self, other: &DirectConnectGatewayState) -> Ordering
fn cmp(&self, other: &DirectConnectGatewayState) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
source§impl PartialEq for DirectConnectGatewayState
impl PartialEq for DirectConnectGatewayState
source§fn eq(&self, other: &DirectConnectGatewayState) -> bool
fn eq(&self, other: &DirectConnectGatewayState) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd for DirectConnectGatewayState
impl PartialOrd for DirectConnectGatewayState
source§fn partial_cmp(&self, other: &DirectConnectGatewayState) -> Option<Ordering>
fn partial_cmp(&self, other: &DirectConnectGatewayState) -> 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 DirectConnectGatewayState
impl StructuralEq for DirectConnectGatewayState
impl StructuralPartialEq for DirectConnectGatewayState
Auto Trait Implementations§
impl RefUnwindSafe for DirectConnectGatewayState
impl Send for DirectConnectGatewayState
impl Sync for DirectConnectGatewayState
impl Unpin for DirectConnectGatewayState
impl UnwindSafe for DirectConnectGatewayState
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
§impl<Q, K> Comparable<K> for Q
impl<Q, K> Comparable<K> for Q
§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.