#[non_exhaustive]
pub enum PayloadFormatIndicator {
UnspecifiedBytes,
Utf8Data,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against PayloadFormatIndicator
, 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 payloadformatindicator = unimplemented!();
match payloadformatindicator {
PayloadFormatIndicator::UnspecifiedBytes => { /* ... */ },
PayloadFormatIndicator::Utf8Data => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when payloadformatindicator
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant PayloadFormatIndicator::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
PayloadFormatIndicator::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 PayloadFormatIndicator::NewFeature
is defined.
Specifically, when payloadformatindicator
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on PayloadFormatIndicator::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
UnspecifiedBytes
Utf8Data
Unknown(UnknownVariantValue)
Unknown
contains new variants that have been added since this code was generated.
Implementations§
Trait Implementations§
source§impl AsRef<str> for PayloadFormatIndicator
impl AsRef<str> for PayloadFormatIndicator
source§impl Clone for PayloadFormatIndicator
impl Clone for PayloadFormatIndicator
source§fn clone(&self) -> PayloadFormatIndicator
fn clone(&self) -> PayloadFormatIndicator
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for PayloadFormatIndicator
impl Debug for PayloadFormatIndicator
source§impl From<&str> for PayloadFormatIndicator
impl From<&str> for PayloadFormatIndicator
source§impl FromStr for PayloadFormatIndicator
impl FromStr for PayloadFormatIndicator
source§impl Hash for PayloadFormatIndicator
impl Hash for PayloadFormatIndicator
source§impl Ord for PayloadFormatIndicator
impl Ord for PayloadFormatIndicator
source§fn cmp(&self, other: &PayloadFormatIndicator) -> Ordering
fn cmp(&self, other: &PayloadFormatIndicator) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
source§impl PartialEq<PayloadFormatIndicator> for PayloadFormatIndicator
impl PartialEq<PayloadFormatIndicator> for PayloadFormatIndicator
source§fn eq(&self, other: &PayloadFormatIndicator) -> bool
fn eq(&self, other: &PayloadFormatIndicator) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd<PayloadFormatIndicator> for PayloadFormatIndicator
impl PartialOrd<PayloadFormatIndicator> for PayloadFormatIndicator
source§fn partial_cmp(&self, other: &PayloadFormatIndicator) -> Option<Ordering>
fn partial_cmp(&self, other: &PayloadFormatIndicator) -> 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 PayloadFormatIndicator
impl StructuralEq for PayloadFormatIndicator
impl StructuralPartialEq for PayloadFormatIndicator
Auto Trait Implementations§
impl RefUnwindSafe for PayloadFormatIndicator
impl Send for PayloadFormatIndicator
impl Sync for PayloadFormatIndicator
impl Unpin for PayloadFormatIndicator
impl UnwindSafe for PayloadFormatIndicator
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.