https://issues.dlang.org/show_bug.cgi?id=13599 --- Comment #3 from Walter Bright <bugzilla at digitalmars.com> --- Workaround, in case it is blocking anyone: (In reply to Walter Bright from comment #2) > E R() > { > foreach ( U ; P ) > return U; > assert(0); return E(); // add this line > } > } --