Using reduce() with tuples created by zip()

[Craig Dillabaugh]

I am trying to calculate the Euclidean Distance between two
points. I currently have the following function (that doesn't
compile):

double euclid_dist( double[] pt1, double[] pt2 ) {
    assert( pt1.length == pt2.length );

    return sqrt(
      zip(pt1, pt2).reduce!(function(e) { return
(e[1]-e[0])*(e[1]-e[0]); })(0.0)
    );
}

Hopefully it is clear what I am trying to do.  I want zip to
create a range that is a tuple of the point's coordinate pairs,
and then use reduce to sum the squared differences.  I get the
following error but can't figure out how to fix my syntax:

euclid.d(13): Error: template
euclid.euclid_dist.reduce!(__funcliteral2).reduce does not match
any function template declaration. Candidates are:
/usr/include/dmd/phobos/std/algorithm.d(688):
euclid.euclid_dist.reduce!(__funcliteral2).reduce(Args...)(Args
args) if (Args.length > 0 && Args.length <= 2 &&
isIterable!(Args[__dollar - 1]))
euclid.d(13): Error: template
euclid.euclid_dist.reduce!(__funcliteral2).reduce(Args...)(Args
args) if (Args.length > 0 && Args.length <= 2 &&
isIterable!(Args[__dollar - 1])) cannot deduce template function
from argument types !()(Zip!(double[], double[]), double)
Failed: 'dmd' '-v' '-o-' 'euclid.d' '-I.'


I know I could use a simple foreach loop with my zip command, or
even std.numeric.euclidean( ... ), but I am trying to be cute
here!

Cheers,
Craig