On Sonntag, 24. September 2017 23:40:45 CEST Miro Kropáček wrote: > How come it's not a problem on other platforms? isblank() is part of the > standard after all. It is only causing problems in the c++98 subfolder. The reason is that in glibc, that macro is only defined for __USE_ISOC99, while in mintlib it is defined for __USE_GNU.