std::string operator , (const std::string& s1, const char* s2)
{
  return s1 + s2;
}

std::string operator , (const char* s1, const std::string& s2)
{
  return s1 + s2;
}

#define TO_STRING_I(n) #n
#define TO_STRING(n) TO_STRING_I(n)
#define FILEPOS __FILE__ "(" TO_STRING(__LINE__) "): "
#define THROW_IF(cond, type, msg, ...) if (cond) throw type((FILEPOS + std::string(msg), __VA_ARGS__).c_str())

struct fatal_error : public std::runtime_error
{
    fatal_error(const char* errormsg)
        : std::runtime_error(errormsg)
    {}
};

inline std::vector<char> read_file(const char* filename)
{
    std::ifstream file(filename, std::ios::binary);
  THROW_IF(!file, fatal_error, "Could not open file: ", filename);
  file.seekg(0, std::ios::end);
    std::vector<char> buf(static_cast<std::vector<char>::size_type>(file.tellg()));
    file.seekg(0, std::ios::beg);
  file.read(&buf[0], buf.size());
  THROW_IF(!file, fatal_error, "Could not read file: ", filename);
  return buf;
}