Use of generics in C11

generics.c

#include <stdio.h>
#include <math.h>

// Define structures for different shapes
typedef struct Rectangle {
    double width;
    double height;
} Rectangle;

typedef struct Circle {
    double radius;
} Circle;

// Generic area function using C11 generics
#define area(shape) _Generic((shape),                  \
    Rectangle: area_rectangle,                         \
    Circle: area_circle                                \
)(shape)

// Specific area implementations
double area_rectangle(Rectangle rect) {
    return rect.width * rect.height;
}

double area_circle(Circle circle) {
    return M_PI * circle.radius * circle.radius;
}

int main() {
    Rectangle rect = {5.0, 3.0};
    Circle circle = {2.5};
    
    // Use the generic area function with different shapes
    printf("Rectangle area: %.2f\n", area(rect));
    printf("Circle area: %.2f\n", area(circle));
    
    return 0;
}