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