Trait CurveAffine

pub trait CurveAffine:
    PrimeCurveAffine<Scalar = Self::ScalarExt, Curve = Self::CurveExt>
    + Default
    + Add<Output = Self::Curve>
    + Sub<Output = Self::Curve>
    + ConditionallySelectable
    + ConstantTimeEq
    + From<Self::Curve> {
    type ScalarExt: WithSmallOrderMulGroup<3> + Ord;
    type Base: WithSmallOrderMulGroup<3> + Ord;
    type CurveExt: CurveExt<AffineExt = Self, ScalarExt = Self::ScalarExt>;

    // Required methods
    fn coordinates(&self) -> CtOption<Coordinates<Self>>;
    fn from_xy(x: Self::Base, y: Self::Base) -> CtOption<Self>;
    fn is_on_curve(&self) -> Choice;
    fn a() -> Self::Base;
    fn b() -> Self::Base;
}

This trait is the affine counterpart to Curve and is used for serialization, storage in memory, and inspection of $x$ and $y$ coordinates.

Requires the alloc feature flag because of hash_to_curve on CurveExt.

Required Associated Types

type ScalarExt: WithSmallOrderMulGroup<3> + Ord

The scalar field of this elliptic curve.

type Base: WithSmallOrderMulGroup<3> + Ord

The base field over which this elliptic curve is constructed.

type CurveExt: CurveExt<AffineExt = Self, ScalarExt = Self::ScalarExt>

The projective form of the curve

Required Methods

fn coordinates(&self) -> CtOption<Coordinates<Self>>

Gets the coordinates of this point.

Returns None if this is the identity.

fn from_xy(x: Self::Base, y: Self::Base) -> CtOption<Self>

Obtains a point given $(x, y)$, failing if it is not on the curve.

fn is_on_curve(&self) -> Choice

Returns whether or not this element is on the curve; should always be true unless an “unchecked” API was used.

fn a() -> Self::Base

Returns the curve constant $a$.

fn b() -> Self::Base

Returns the curve constant $b$.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl CurveAffine for EpAffine

type ScalarExt = Fq

type Base = Fp

type CurveExt = Ep

impl CurveAffine for EqAffine

type ScalarExt = Fp

type Base = Fq

type CurveExt = Eq