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