Why do ints defined in template mixins have garbage values?

[Johannes Riecken via Digitalmars-d-learn]

Code:

import std.conv;
import std.stdio;

mixin template genInts()
{
  enum arr = [0,1];
  static foreach (t; arr) {
    mixin("int i" ~ to!string(t) ~ " = 5;");
  }
}

void main() {
  mixin genInts!();
  writeln(i0);
  writeln(i1);
}


Expected output:
5
5

Actual output is two garbage integer values.