Struct StrictlyNegative

pub struct StrictlyNegative;

Marker type enforcing that a value is strictly negative (less than zero).

Use this type with Constrained<T, StrictlyNegative> to encode strict negativity at the type level.

You can construct a value constrained to be strictly negative using either the generic Constrained::new method or the convenient StrictlyNegative::new associated function.

Examples

use twine_core::constraint::{Constrained, StrictlyNegative};

// Generic constructor:
let x = Constrained::<_, StrictlyNegative>::new(-1).unwrap();
assert_eq!(x.into_inner(), -1);

// Associated constructor:
let y = StrictlyNegative::new(-2.5).unwrap();
assert_eq!(y.into_inner(), -2.5);

// Error cases:
assert!(StrictlyNegative::new(0).is_err());
assert!(StrictlyNegative::new(3).is_err());
assert!(StrictlyNegative::new(f64::NAN).is_err());

Implementations

impl StrictlyNegative

pub fn new<T: PartialOrd + Zero>( value: T, ) -> Result<Constrained<T, StrictlyNegative>, ConstraintError>

Constructs a Constrained<T, StrictlyNegative> if the value is strictly negative.

Errors

Returns an error if the value is zero, positive, or not a number (NaN).

Trait Implementations

impl Clone for StrictlyNegative

fn clone(&self) -> StrictlyNegative

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: PartialOrd + Zero> Constraint<T> for StrictlyNegative

fn check(value: &T) -> Result<(), ConstraintError>

Checks that the given value satisfies this constraint.

impl Debug for StrictlyNegative

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for StrictlyNegative

fn eq(&self, other: &StrictlyNegative) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for StrictlyNegative

impl Eq for StrictlyNegative

impl StructuralPartialEq for StrictlyNegative