#[non_exhaustive]
pub enum AutoEnableStandards {
Default,
None,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against AutoEnableStandards
, 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 autoenablestandards = unimplemented!();
match autoenablestandards {
AutoEnableStandards::Default => { /* ... */ },
AutoEnableStandards::None => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when autoenablestandards
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant AutoEnableStandards::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
AutoEnableStandards::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 AutoEnableStandards::NewFeature
is defined.
Specifically, when autoenablestandards
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on AutoEnableStandards::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
Default
None
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl AsRef<str> for AutoEnableStandards
impl AsRef<str> for AutoEnableStandards
source§impl Clone for AutoEnableStandards
impl Clone for AutoEnableStandards
source§fn clone(&self) -> AutoEnableStandards
fn clone(&self) -> AutoEnableStandards
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for AutoEnableStandards
impl Debug for AutoEnableStandards
source§impl From<&str> for AutoEnableStandards
impl From<&str> for AutoEnableStandards
source§impl FromStr for AutoEnableStandards
impl FromStr for AutoEnableStandards
source§impl Hash for AutoEnableStandards
impl Hash for AutoEnableStandards
source§impl Ord for AutoEnableStandards
impl Ord for AutoEnableStandards
source§fn cmp(&self, other: &AutoEnableStandards) -> Ordering
fn cmp(&self, other: &AutoEnableStandards) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
source§impl PartialEq<AutoEnableStandards> for AutoEnableStandards
impl PartialEq<AutoEnableStandards> for AutoEnableStandards
source§fn eq(&self, other: &AutoEnableStandards) -> bool
fn eq(&self, other: &AutoEnableStandards) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd<AutoEnableStandards> for AutoEnableStandards
impl PartialOrd<AutoEnableStandards> for AutoEnableStandards
source§fn partial_cmp(&self, other: &AutoEnableStandards) -> Option<Ordering>
fn partial_cmp(&self, other: &AutoEnableStandards) -> 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 AutoEnableStandards
impl StructuralEq for AutoEnableStandards
impl StructuralPartialEq for AutoEnableStandards
Auto Trait Implementations§
impl RefUnwindSafe for AutoEnableStandards
impl Send for AutoEnableStandards
impl Sync for AutoEnableStandards
impl Unpin for AutoEnableStandards
impl UnwindSafe for AutoEnableStandards
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.