I wouldn't state it is the best way but you can try something like that:
```D
import std.complex;
import std.range : zip;
import std.algorithm : equal, map;
import std.array : array;
void main(){
auto N=2;
double[] x,y;
x.length = N;
y.length = N;
x[0] = 1.1;
x[1] = 2.2;
y[0] = 3.3;
y[1] = 4.4;
auto z = zip(x, y) // concatenate two ranges
.map!(a=>Complex!double(a[0],a[1])) // take the current first
element of the first range as the real part and the current first
element of the second range as the imaginary part
.array; // convert the lazy range
to a dynamic array, probably you can avoid but this depends on how you
use it later
assert(z.equal([
Complex!double(1.1, 3.3),
Complex!double(2.2, 4.4),
]));
}
```D
