fabs(x) vs. (x) < 0 ? -(x) : (x)

[ark at alice.UUCP]

If you were doing it in C++, you could say:

	inline double fabs (double x)
		{ return x < 0? -x: x; }

and it would do the right thing, efficiently.  Moreover, you could say:

	overload abs;

	inline double abs (double x)
		{ return x < 0? -x: x; }
	inline long abs (long x)
		{ return x < 0? -x: x; }
	inline int abs (int x)
		{ return x < 0? -x: x; }
	inline float abs (float x)
		{ return x < 0? -x: x; }

and not have to remember the type of your arguments.  Generalizing
the second example above to an unbounded family of types is left
as an exercise for the reader.