C 語言變體長

// main.h
/*
	
*/
typedef struct{
	int cost;
	int supplier;
}Partinfo;

typedef struct SUBASSYPART{
		char partno[10];
		short quan;	
}subassyinfo;

/*

*/
typedef struct {
	int n_parts;
	subassyinfo *part;
}Subassyinfo;

/*

*/
typedef struct{
	char partno[10];
	int quan;
	enum {PART,SUBASSY} type;
	union{
		Partinfo *part;
		Subassyinfo *subassy;
	}info;
}Invrec;

// main.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "main.h"

Invrec *create_subassy_record(int n_parts);
Invrec *create_part_record(int n_partno);
void destory_subassy_record(Invrec *new_rec);
void destory_part_recored(Invrec *new_rec);

//加入析構函數

int main()
{

	char b[10]={'a','b','c','d','e','f'};
	Invrec* a;
	a = (Invrec*)malloc(sizeof(Invrec));

	if(a != NULL)
	{
		a = create_subassy_record(10);

		a->info.subassy->part->quan=100;
		a->quan=100;
		memcpy(a->partno,b,sizeof(b));
		memcpy(a->info.subassy->part->partno,b,sizeof(b));
	}



	printf("%d\r\n",a->info.subassy->n_parts);

	destory_subassy_record(a);
	if(a != NULL){
		a  = create_part_record(100);
	}
	printf("%d\r\n",a->info.part->cost);
	destory_part_recored(a);
	return 0;
}


Invrec *create_subassy_record(int n_partno)
{
	Invrec *new_rec;

	new_rec = (Invrec*)malloc(sizeof(Invrec));

	if(new_rec != NULL){
		new_rec->info.subassy = (Subassyinfo*)malloc(sizeof(Subassyinfo));

		if(new_rec->info.subassy != NULL){
			new_rec->type = SUBASSY;
			new_rec->info.subassy->n_parts = n_partno;

			new_rec->info.subassy->part  = (subassyinfo*)malloc(sizeof(subassyinfo));
			if(new_rec->info.subassy->part != NULL)
			{
				return new_rec;
			}
			free(new_rec->info.subassy->part);
		}
	
		free(new_rec->info.subassy);
	}	

	free(new_rec);
	return NULL;
}

void destory_subassy_record(Invrec* a)
{
	if(a->type == SUBASSY)
	{
		free(a->info.subassy->part);
		free(a->info.subassy);
		free(a);
	}

}

Invrec* create_part_record(int cost)
{
	Invrec *new_rec;

	new_rec = (Invrec*)malloc(sizeof(Invrec));

	if(new_rec != NULL){
		new_rec->info.part = (Partinfo*)malloc(sizeof(Partinfo));
		if(new_rec->info.part != NULL)
		{
			new_rec->type = PART;
			new_rec->info.part->cost = cost;
			return new_rec;
		}

		free(new_rec->info.part);

	}
	free(new_rec);
	return NULL;
}


void destory_part_recored(Invrec *a)
{
	if(a->type == PART)
	{
		free(a->info.part);
		free(a);
	}
}