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