=================================================== 4.14 swap that interchanges two arguments of type t =================================================== Question ======== Define a macro swap(t,x,y) that interchanges two arguments of type t. .. coderun:: cprogs/ex_4.14_swap_t_x_y.c :language: c Explanation =========== There are two types of macros in C namely object-like and function-like. In object type, we do substitution and in function macros we can send a variable as argument. In this program we are going to use function-like macro to swap. We do this by defining macro:: #define swap(t,x,y) { t _z; \ _z = x;\ x = y;\ y = _z; } In the macro, we send type `t` as an argument and two variables `x` and `y` to swap. We create a temperorary variable called `_z` of type `t` and use it to swap `x` and `y`. Visualize the Full Solution --------------------------- .. raw:: html Visualize the Concept --------------------- .. raw:: html