Enum extendr_api::wrapper::Nullable [−][src]
Wrapper for handling potentially NULL values.
use extendr_api::prelude::*; test! { use extendr_api::wrapper::Nullable::*; // Plain integer. let s1 = r!(1); let n1 = <Nullable<i32>>::from_robj(&s1)?; assert_eq!(n1, NotNull(1)); // NA integer - error. let sna = r!(NA_INTEGER); assert_eq!(<Nullable<i32>>::from_robj(&sna).is_err(), true); // NA integer - option gives none. assert_eq!(<Nullable<Option<i32>>>::from_robj(&sna)?, NotNull(None)); // NULL object. let snull = r!(NULL); let nnull = <Nullable<i32>>::from_robj(&snull)?; assert_eq!(nnull, Null); assert_eq!(r!(Nullable::<i32>::Null), r!(NULL)); assert_eq!(r!(Nullable::<i32>::NotNull(1)), r!(1)); }
Variants
Trait Implementations
impl<T: Clone> Clone for Nullable<T>
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impl<T: Debug> Debug for Nullable<T>
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impl<T> From<Nullable<T>> for Robj where
T: Into<Robj>,
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T: Into<Robj>,
fn from(val: Nullable<T>) -> Self
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Convert a rust object to NULL or another type.
use extendr_api::prelude::*; test! { assert_eq!(r!(Nullable::<i32>::Null), r!(NULL)); assert_eq!(r!(Nullable::<i32>::NotNull(1)), r!(1)); }
impl<'a, T> FromRobj<'a> for Nullable<T> where
T: FromRobj<'a>,
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T: FromRobj<'a>,
fn from_robj(robj: &'a Robj) -> Result<Self, &'static str>
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Convert an object that may be null to a rust type.
use extendr_api::prelude::*; test! { let s1 = r!(1); let n1 = <Nullable<i32>>::from_robj(&s1)?; assert_eq!(n1, Nullable::NotNull(1)); let snull = r!(NULL); let nnull = <Nullable<i32>>::from_robj(&snull)?; assert_eq!(nnull, Nullable::Null); }
impl<T: PartialEq> PartialEq<Nullable<T>> for Nullable<T>
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impl<T> StructuralPartialEq for Nullable<T>
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Auto Trait Implementations
impl<T> RefUnwindSafe for Nullable<T> where
T: RefUnwindSafe,
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T: RefUnwindSafe,
impl<T> Send for Nullable<T> where
T: Send,
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T: Send,
impl<T> Sync for Nullable<T> where
T: Sync,
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T: Sync,
impl<T> Unpin for Nullable<T> where
T: Unpin,
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T: Unpin,
impl<T> UnwindSafe for Nullable<T> where
T: UnwindSafe,
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T: UnwindSafe,
Blanket Implementations
impl<T> Any for T where
T: 'static + ?Sized,
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T: 'static + ?Sized,
impl<T> Borrow<T> for T where
T: ?Sized,
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T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
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T: ?Sized,
pub fn borrow_mut(&mut self) -> &mut T
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impl<T> From<T> for T
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impl<T, U> Into<U> for T where
U: From<T>,
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U: From<T>,
impl<T> ToOwned for T where
T: Clone,
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T: Clone,
type Owned = T
The resulting type after obtaining ownership.
pub fn to_owned(&self) -> T
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pub fn clone_into(&self, target: &mut T)
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impl<T, U> TryFrom<U> for T where
U: Into<T>,
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U: Into<T>,
type Error = Infallible
The type returned in the event of a conversion error.
pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
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impl<T, U> TryInto<U> for T where
U: TryFrom<T>,
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U: TryFrom<T>,