[C language] how to implement plural types

First statement ： stay C99 Plural types are already supported in the standard .
Don't talk about this here , If you want to know something, you can check it directly , Let's talk about the implementation of complex types and operations . It's also very simple , Directly defining a simple structure and related arithmetic functions is OK 了 .
Here is the implementation process ：

#include "stdio.h"
#define Real(c) (c).real
#define Imag(c) (c).imag

typedef struct {
    
	double real;
	double imag;
}complex;

complex cpx_make(double real, double imag)
{
    
	complex ret;
	ret.real = real;
	ret.imag = imag;
	return ret;
}

complex cpx_add(complex a, complex b)
{
    
	return cpx_make(Real(a) + Real(b), Imag(a) + Imag(b));
}

int main()
{
    
	complex a = cpx_make(1, 2);
	complex b = cpx_make(3, 4);

	// It can also be written directly as follows 
	printf("%f", cpx_add(cpx_make(1, 2), cpx_make(3, 4)));
	return 0;
}