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