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