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