How to get the file separator symbol in standard C/C++ : / or \?

Question

I would like to write a function :

inline char separator()
{
    /* SOMETHING */
}

that returns the file separator of the system in standar

Answer 1

The accepted answer does not work under Cygwin. Cygwin compiled programs running on Windows can use the Windows style '\' separator, but it does not define _WIN32 or the likes. A modified solution that works under Cygwin:

inline char separator()
{
#if defined _WIN32 || defined __CYGWIN__
    return '\\';
#else
    return '/';
#endif
}

or

const char kPathSeparator =
#if defined _WIN32 || defined __CYGWIN__
    '\\';
#else
    '/';
#endif