char			a b			swap 	b a
signed int		-1 -2			swap 	-2 -1
unsigned int		1 2			swap 	2 1
signed long int		-1 -2			swap 	-2 -1
unsigned long int	1 2			swap 	2 1
signed long long int	-1 -2			swap 	-2 -1
unsigned long long int	1 2			swap 	2 1
float			1.5 2.5			swap 	2.5 1.5
double			1.5 2.5			swap 	2.5 1.5
long double		1.5 2.5			swap 	2.5 1.5
float _Complex		1.5+1.5i 2.5+2.5i	swap 	2.5+2.5i 1.5+1.5i
double _Complex		1.5+1.5i 2.5+2.5i	swap 	2.5+2.5i 1.5+1.5i
long double _Complex	1.5+1.5i 2.5+2.5i	swap 	2.5+2.5i 1.5+1.5i
struct S		1 2, 2 1		swap 	2 1, 1 2
