#[non_exhaustive]pub enum Ros2PrimitiveType {
Show 16 variants
Bool,
Byte,
Char,
Float32,
Float64,
Int16,
Int32,
Int64,
Int8,
String,
Uint16,
Uint32,
Uint64,
Uint8,
Wstring,
Unknown(UnknownVariantValue),
}
Expand description
When writing a match expression against Ros2PrimitiveType
, 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 ros2primitivetype = unimplemented!();
match ros2primitivetype {
Ros2PrimitiveType::Bool => { /* ... */ },
Ros2PrimitiveType::Byte => { /* ... */ },
Ros2PrimitiveType::Char => { /* ... */ },
Ros2PrimitiveType::Float32 => { /* ... */ },
Ros2PrimitiveType::Float64 => { /* ... */ },
Ros2PrimitiveType::Int16 => { /* ... */ },
Ros2PrimitiveType::Int32 => { /* ... */ },
Ros2PrimitiveType::Int64 => { /* ... */ },
Ros2PrimitiveType::Int8 => { /* ... */ },
Ros2PrimitiveType::String => { /* ... */ },
Ros2PrimitiveType::Uint16 => { /* ... */ },
Ros2PrimitiveType::Uint32 => { /* ... */ },
Ros2PrimitiveType::Uint64 => { /* ... */ },
Ros2PrimitiveType::Uint8 => { /* ... */ },
Ros2PrimitiveType::Wstring => { /* ... */ },
other @ _ if other.as_str() == "NewFeature" => { /* handles a case for `NewFeature` */ },
_ => { /* ... */ },
}
The above code demonstrates that when ros2primitivetype
represents
NewFeature
, the execution path will lead to the second last match arm,
even though the enum does not contain a variant Ros2PrimitiveType::NewFeature
in the current version of SDK. The reason is that the variable other
,
created by the @
operator, is bound to
Ros2PrimitiveType::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 Ros2PrimitiveType::NewFeature
is defined.
Specifically, when ros2primitivetype
represents NewFeature
,
the execution path will hit the second last match arm as before by virtue of
calling as_str
on Ros2PrimitiveType::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
Bool
Byte
Char
Float32
Float64
Int16
Int32
Int64
Int8
String
Uint16
Uint32
Uint64
Uint8
Wstring
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 Ros2PrimitiveType
impl Ros2PrimitiveType
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 Ros2PrimitiveType
impl AsRef<str> for Ros2PrimitiveType
source§impl Clone for Ros2PrimitiveType
impl Clone for Ros2PrimitiveType
source§fn clone(&self) -> Ros2PrimitiveType
fn clone(&self) -> Ros2PrimitiveType
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for Ros2PrimitiveType
impl Debug for Ros2PrimitiveType
source§impl From<&str> for Ros2PrimitiveType
impl From<&str> for Ros2PrimitiveType
source§impl FromStr for Ros2PrimitiveType
impl FromStr for Ros2PrimitiveType
source§impl Hash for Ros2PrimitiveType
impl Hash for Ros2PrimitiveType
source§impl Ord for Ros2PrimitiveType
impl Ord for Ros2PrimitiveType
source§fn cmp(&self, other: &Ros2PrimitiveType) -> Ordering
fn cmp(&self, other: &Ros2PrimitiveType) -> 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 Ros2PrimitiveType
impl PartialEq for Ros2PrimitiveType
source§fn eq(&self, other: &Ros2PrimitiveType) -> bool
fn eq(&self, other: &Ros2PrimitiveType) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd for Ros2PrimitiveType
impl PartialOrd for Ros2PrimitiveType
source§fn partial_cmp(&self, other: &Ros2PrimitiveType) -> Option<Ordering>
fn partial_cmp(&self, other: &Ros2PrimitiveType) -> 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 Ros2PrimitiveType
impl StructuralEq for Ros2PrimitiveType
impl StructuralPartialEq for Ros2PrimitiveType
Auto Trait Implementations§
impl RefUnwindSafe for Ros2PrimitiveType
impl Send for Ros2PrimitiveType
impl Sync for Ros2PrimitiveType
impl Unpin for Ros2PrimitiveType
impl UnwindSafe for Ros2PrimitiveType
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.