https://issues.dlang.org/show_bug.cgi?id=17381
--- Comment #1 from Berni44 <bugzi...@bernis-buecher.de> --- Meanwhile I found the reason for this: When checking at compile time, there is a cannot-format-floats-at-compiletime-exception thrown. For testing purpose this is ignored (as it is supposed to work in runtime) and hence the orphan-arguments-exception overlooked. Meanwhile format is able to format floats and doubles at compiletime (but yet not reals). Therefore the code above works meanwhile, but not with 1.5L yet. --