_IS_DRIVE_LETTER 63 maint/gnulib/lib/filename.h # define _IS_DRIVE_LETTER(C) \ _IS_DRIVE_LETTER 66 maint/gnulib/lib/filename.h # undef _IS_DRIVE_LETTER _IS_DRIVE_LETTER 67 maint/gnulib/lib/filename.h # define _IS_DRIVE_LETTER(C) \