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