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