Question

I am building a cmake project that includes cuda code. I am unable to compile one of the cuda files that includes several h files. This is the compiler error I receive

In file included from /usr/include/c++/4.4/bits/basic_ios.h:39,
                 from /usr/include/c++/4.4/ios:45,
                 from /usr/include/c++/4.4/ostream:40,
                 from /usr/include/c++/4.4/iostream:40,
                 from /home/pfeifs/Developement/Deform/LinuxDeform/LibDeform/Deform/cutil_comfunc.h:20,
                 from /home/pfeifs/Developement/Deform/LinuxDeform/LibDeform/Deform/VectorMathDef.h:22,
                 from /home/pfeifs/Developement/Deform/LinuxDeform/LibDeform/src/Deform/VectorMath.cu:15:
/usr/include/c++/4.4/bits/locale_facets.h:2521:44: error: macro "isspace" passed 2 arguments, but takes just 1

isspace() is defined as a macro requiring one argument in <ctype.h> and declared as a templated function in locale_facets.h. (These are both standard files.) However at the beginning of locale_facets.h, <cctype> is included and that undeclares the macro.

Any help or insight into this problem is greatly appreciated.

Answer 1

Do not mix and match C and C++ headers.

Use #include <locale> to pull in the std::isspace template with two parameters. Use #include <cctype> for a C++ safe include of ctype.h that won’t cause conflicts with STL.

If you are writing a C program and don’t want or need C++ then there should be no problem including ctype.h and using the isspace function with only one parameter.