error: ‘void __stderrp(MattsMatrixSpace::Vec)’ redeclared as different kind of symbol

I have a function called "stderr" in my program. I'm not sure where the "__" or the "p" came from. Any idea what this error is related to?


PS, the next error is: /usr/include/stdio.h:169: error: previous declaration of ‘FILE* __stderrp’

In C, there is stdin, stdout and stderr, which are the standard I/O streams.

Call your function something else.