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.
http://dsource.org/projects/phobos/changeset/1914
*** Issue 4840 has been marked as a duplicate of this issue. ***