Function real_rrule 

pub fn real_rrule<S: ComplexProjectionScalar>(cotangent: S::Real) -> S

Reverse rule for real.

Examples

use chainrules::real_rrule;
use num_complex::Complex64;

let grad: Complex64 = real_rrule(2.0);
assert_eq!(grad, Complex64::new(2.0, 0.0));