CCC

嘗試用C實作了simple factory如下

#include 

typedef void (*Method)(void);

typedef struct Interface {
 Method method;
} Interface;


void good_method(void)
{
 printf("good\n");
}

void bad_method(void)
{
 printf("bad\n");
}

Interface* New_Product(char* type)
{
 Interface* ret = (Interface*) malloc(sizeof(Interface));
 if( strcmp(type, "good") == 0 ) {
  ret->method = good_method;
 } else if( strcmp(type, "bad") == 0) {
  ret->method = bad_method;
 } else {
  return NULL;
 }
 return ret;
}

int main(void)
{
 Interface* product;
 product = New_Product("bad");
 product->method();
 product = New_Product("good");
 product->method();
 product = New_Product("bad");
 if( product == NULL ) 
  printf("nothing");
 else
  product->method();

 return 0;
}