I have posted two pull requests around value formatting/unformatting features. (They are yet not merged.) Improve std.format.formatValue https://github.com/D-Programming-Language/phobos/pull/126 Improve value unformatting https://github.com/D-Programming-Language/phobos/pull/208 After their merging into Phobos, std.conv.to can use them for value to string. I think we should consolidate formatting/unformatting functions into std.format.
I have posted a pull request to fix this issue: https://github.com/D-Programming-Language/phobos/pull/236 And it was merged in dmd 2.057.