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