Scalar + array operations

[Stefan Frijters via Digitalmars-d-learn]

When working on my current project (writing a numerical 
simulation code) I ran into the following issue when trying to 
multiply a vector (represented by a fixed-length array) by a 
scalar:

import std.stdio;
void main() {
  int ifoo = 2;
  int[3] ibar = 1;

  double dfoo = 2.0;
  double[3] dbar = 1.0;

  dfoo = ifoo * dfoo;      // Scalar int * scalar double -- OK
  writeln(dfoo);
  dfoo = dfoo * dfoo;      // Scalar double * scalar double -- OK
  writeln(dfoo);
  dbar = dfoo * dbar[];    // Scalar double * array of double -- 
OK
  writeln(dbar);
  ibar = ifoo * ibar[];    // Scalar int * array of int -- OK
  writeln(ibar);
  dbar = ifoo * dbar[];    // Scalar int * array of double -- OK
  writeln(dbar);
  // dbar = dfoo * ibar[]; // Scalar double * array of int -- FAIL
  // writeln(dbar);
}

I would have expected the last case to work as well, but I get

testarr.d(20): Error: incompatible types for ((dfoo) * (ibar[])): 
'double' and 'int[]'

Is this by design? It was very surprising to me, especially since 
all other combinations do seem to work.

Kind regards,

Stefan Frijters