#ifndef DIE_H_INCLUDED
#define DIE_H_INCLUDED

// die is used like this:
//
// if (n<3)
//      die << "How did n get as small as " << n << "?";
//
// It will print the message to cerr, and exit(1).
//
// A newline is *not* required; it is supplied automatically.
//
// Implementation features:
// • die is a macro that creates a temporary Death object whose
//   destructor is called at the semicolon, the message is displayed,
//   and exit is called.
// • operator<< as a const method, not a free function
// • conditional compilation for non-standard acquisition of argv[0]
// • string pasting
// • const char *const
// • __func__

#define die Death(__func__, __FILE__, __LINE__)

#include <cstdlib>			// exit()
#include <iostream>			// cerr

#if __hpux
  extern "C" const char **__argv_value; // HP-UX program name
#elif __linux
  #include <cerrno>			// Linux program name
#else
  #error Cannot display argv[0].
#endif

class Death {
    const char *const func, *const file; const int line;
  public:
    Death(const char *fu, const char *fi, int li) : func(fu), file(fi), line(li) {
	*this << "\nFatal error: ";
    }
    ~Death() {
	*this << "\n"
#if __hpux
		 "Program: "	<< __argv_value[0]	   << "\n"
#elif __linux
		 "Program: "	<< program_invocation_name << "\n"
#endif
		 "Function: "	<< func			   << "\n"
		 "File: "	<< file			   << "\n"
		 "Line: "	<< line			   << "\n"
		 "Exiting.\n";
	std::exit(1);
    }
    template <typename T>
    std::ostream& operator<<(T const &item) const {
	return std::cerr << item;
    }
};

#endif /* DIE_H_INCLUDED */