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