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