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