Function safe_str

library/Error.cpp:9–12

using namespace DFHack::Error;

inline std::string safe_str(const char *s)
{
    return s ? s : "(NULL)";
}

NullPointer::NullPointer(const char *varname, const char *func)
    :All("In " + safe_str(func) + ": NULL pointer: " + safe_str(varname)),