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