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