#[non_exhaustive]pub enum ContentType {
ApplicationJson,
UrlEncoded,
Unknown(UnknownVariantValue),
}Expand description
When writing a match expression against ContentType, 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 contenttype = unimplemented!();
match contenttype {
ContentType::ApplicationJson => { /* ... */ },
ContentType::UrlEncoded => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}The above code demonstrates that when contenttype represents
NewFeature, the execution path will lead to the second last match arm,
even though the enum does not contain a variant ContentType::NewFeature
in the current version of SDK. The reason is that the variable other,
created by the @ operator, is bound to
ContentType::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 ContentType::NewFeature is defined.
Specifically, when contenttype represents NewFeature,
the execution path will hit the second last match arm as before by virtue of
calling as_str on ContentType::NewFeature also yielding "NewFeature".
Explicitly matching on the Unknown variant should
be avoided for two reasons:
- The inner data
UnknownVariantValueis 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
ApplicationJson
UrlEncoded
Unknown(UnknownVariantValue)
Don’t directly match on 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 ContentType
impl ContentType
Source§impl ContentType
impl ContentType
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 ContentType
impl AsRef<str> for ContentType
Source§impl Clone for ContentType
impl Clone for ContentType
Source§fn clone(&self) -> ContentType
fn clone(&self) -> ContentType
1.0.0 (const: unstable) · Source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source. Read moreSource§impl Debug for ContentType
impl Debug for ContentType
Source§impl Display for ContentType
impl Display for ContentType
Source§impl From<&str> for ContentType
impl From<&str> for ContentType
Source§impl FromStr for ContentType
impl FromStr for ContentType
Source§impl Hash for ContentType
impl Hash for ContentType
Source§impl Ord for ContentType
impl Ord for ContentType
Source§fn cmp(&self, other: &ContentType) -> Ordering
fn cmp(&self, other: &ContentType) -> Ordering
1.21.0 (const: unstable) · Source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
Source§impl PartialEq for ContentType
impl PartialEq for ContentType
Source§fn eq(&self, other: &ContentType) -> bool
fn eq(&self, other: &ContentType) -> bool
self and other values to be equal, and is used by ==.Source§impl PartialOrd for ContentType
impl PartialOrd for ContentType
impl Eq for ContentType
impl StructuralPartialEq for ContentType
Auto Trait Implementations§
impl Freeze for ContentType
impl RefUnwindSafe for ContentType
impl Send for ContentType
impl Sync for ContentType
impl Unpin for ContentType
impl UnsafeUnpin for ContentType
impl UnwindSafe for ContentType
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<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
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§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key and return true if they are equal.Source§impl<T> Instrument for T
impl<T> Instrument for T
Source§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
Source§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
Source§impl<T> IntoEither for T
impl<T> IntoEither for T
Source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
self into a Left variant of Either<Self, Self>
if into_left is true.
Converts self into a Right variant of Either<Self, Self>
otherwise. Read moreSource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
self into a Left variant of Either<Self, Self>
if into_left(&self) returns true.
Converts self into a Right variant of Either<Self, Self>
otherwise. Read more