Enum aorist_extendr_api::wrapper::nullable::Nullable [−][src]
pub enum Nullable<T> { NotNull(T), Null, }
Expand description
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
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); }
Auto Trait Implementations
impl<T> RefUnwindSafe for Nullable<T> where
T: RefUnwindSafe,
impl<T> UnwindSafe for Nullable<T> where
T: UnwindSafe,
Blanket Implementations
Mutably borrows from an owned value. Read more