Enum aws_sdk_elasticache::model::IpDiscovery
source · #[non_exhaustive]
pub enum IpDiscovery {
Ipv4,
Ipv6,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against IpDiscovery
, 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 ipdiscovery = unimplemented!();
match ipdiscovery {
IpDiscovery::Ipv4 => { /* ... */ },
IpDiscovery::Ipv6 => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when ipdiscovery
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant IpDiscovery::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
IpDiscovery::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 IpDiscovery::NewFeature
is defined.
Specifically, when ipdiscovery
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on IpDiscovery::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
Ipv4
Ipv6
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl AsRef<str> for IpDiscovery
impl AsRef<str> for IpDiscovery
source§impl Clone for IpDiscovery
impl Clone for IpDiscovery
source§fn clone(&self) -> IpDiscovery
fn clone(&self) -> IpDiscovery
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for IpDiscovery
impl Debug for IpDiscovery
source§impl From<&str> for IpDiscovery
impl From<&str> for IpDiscovery
source§impl FromStr for IpDiscovery
impl FromStr for IpDiscovery
source§impl Hash for IpDiscovery
impl Hash for IpDiscovery
source§impl Ord for IpDiscovery
impl Ord for IpDiscovery
source§fn cmp(&self, other: &IpDiscovery) -> Ordering
fn cmp(&self, other: &IpDiscovery) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
source§impl PartialEq<IpDiscovery> for IpDiscovery
impl PartialEq<IpDiscovery> for IpDiscovery
source§fn eq(&self, other: &IpDiscovery) -> bool
fn eq(&self, other: &IpDiscovery) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd<IpDiscovery> for IpDiscovery
impl PartialOrd<IpDiscovery> for IpDiscovery
source§fn partial_cmp(&self, other: &IpDiscovery) -> Option<Ordering>
fn partial_cmp(&self, other: &IpDiscovery) -> 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 IpDiscovery
impl StructuralEq for IpDiscovery
impl StructuralPartialEq for IpDiscovery
Auto Trait Implementations§
impl RefUnwindSafe for IpDiscovery
impl Send for IpDiscovery
impl Sync for IpDiscovery
impl Unpin for IpDiscovery
impl UnwindSafe for IpDiscovery
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.