Struct printf macro and explain C compile time str concatenation.

struct_printf.c

/*
 Tymon Woźniak <https://github.com/Moderrek>
 C compile time concatenation
 Struct printf
*/
#include <stdio.h>

// struct print format
#define Point_Fmt "(%d, %d)"
// unpack struct
#define Point_Arg(p) p.x, p.y

typedef struct {
    int x, y;
} Point;

int main() {
    Point p = { .x = 5, .y = 2 };
    // C compile time concatenation
    printf("Compile""Time :D\n");
    // Cool format
    printf("Point "Point_Fmt"\n", Point_Arg(p));
    //            ^^       ^^             ^
    //        Compile time concat       Unpack
    // bad
    printf("Point (%d, %d)\n", p.x, p.y);
    // imagine a much more complicated structure and writing it out at every moment of the program
    // plus struct change :)
    return 0;
}