import std.conv;
auto zero = to!double("0");
fails with core.exception.AssertError@f:\dmd2\windows\bin\..\..\src\phobos\std\array.d(362): Attempting to fetch the front of an empty array
It doesn't matter if you convert to float, double or real.
Converting ".0" and "0.0" works fine.
It works fine on dmd-2.042.