signed char		-65		abs 65
signed int		-65		abs 65
signed long int		-65		abs 65
signed long long int	-65		abs 65
float			-65.		abs 65.
double			-65.		abs 65.
long double		-65.		abs 65.
float _Complex		-65.-2.i	abs 65.0308
double _Complex		-65.-2.i	abs 65.0307619515564
long double _Complex	-65.-2.i	abs 65.0307619515564342
user type		(-3, -4)	abs (3, 4)
