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