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