function zfill( N, alpha, x, strideX, offsetX ) {
	var view;
	var re;
	var im;
	var ix;
	var m;
	var i;

	if ( N <= 0 ) {
		return x;
	}

	// Decompose the constant into its real and imaginary components:
	re = real( alpha );
	im = imag( alpha );

	// Reinterpret the complex input array as a real-valued array:
	view = reinterpret( x, 0 );

	// Adjust the stride and offset according to real-valued array:
	ix = offsetX * 2;
	strideX *= 2;

	// Use loop unrolling if the stride is equal to `2`...
	if ( strideX === 2 ) {
		m = N % M;

		// If we have a remainder, run a clean-up loop...
		if ( m > 0 ) {
			for ( i = 0; i < m; i++ ) {
				view[ ix ] = re;
				view[ ix+1 ] = im;
				ix += strideX;
			}
		}
		if ( N < M ) {
			return x;
		}
		for ( i = m; i < N; i += M ) {
			view[ ix ] = re;
			view[ ix+1 ] = im;
			view[ ix+2 ] = re;
			view[ ix+3 ] = im;
			view[ ix+4 ] = re;
			view[ ix+5 ] = im;
			view[ ix+6 ] = re;
			view[ ix+7 ] = im;
			view[ ix+8 ] = re;
			view[ ix+9 ] = im;
			view[ ix+10 ] = re;
			view[ ix+11 ] = im;
			view[ ix+12 ] = re;
			view[ ix+13 ] = im;
			view[ ix+14 ] = re;
			view[ ix+15 ] = im;
			ix += M * 2;
		}
		return x;
	}
	for ( i = 0; i < N; i++ ) {
		view[ ix ] = re;
		view[ ix+1 ] = im;
		ix += strideX;
	}
	return x;
}
Fills a double-precision complex floating-point strided array with a specified scalar constant.

@param {PositiveInteger} N - number of indexed elements
@param {ComplexLike} alpha - scalar constant
@param {Complex128Array} x - input array
@param {integer} strideX - index increment
@param {NonNegativeInteger} offsetX - starting index
@returns {Complex128Array} input array

@example
var Float64Array = require( '@stdlib/array/float64' );
var Complex128Array = require( '@stdlib/array/complex128' );
var Complex128 = require( '@stdlib/complex/float64/ctor' );
var real = require( '@stdlib/complex/float64/real' );
var imag = require( '@stdlib/complex/float64/imag' );

var arr = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ] );
var x = new Complex128Array( arr );

var alpha = new Complex128( 10.0, 10.0 );

zfill( x.length, alpha, x, 1, 0 );

var y = x.get( 0 );
// returns <Complex128>

var re = real( y );
// returns 10.0

var im = imag( y );
// returns 10.0