Dealing with nested if then else/nested switch statements

function doWork(object x)
{

   if (x is a type of Apple)
   {
      x.Eat();

   } else if (x is a type of Orange)
   {
      x.Peel();
      x.Eat();
   }

}

class FruitFactory
{
   Fruit GetMeMoreFruit(typeOfFruit)
   {
         switch (typeOfFruit)
         ...
         ...
   }
}

class X {
public:
	int get_type();		/* Or an enum return type or similar */
	...
};

void eat(X& x) {
	switch (x.get_type()) {
	TYPE_A: eat_A(x); break;
	TYPE_B: eat_B(x); break;
	TYPE_C: eat_C(x); break;
	}
}

void drink(X& x) {
	switch (x.get_type()) {
	TYPE_A: drink_A(x); break;
	TYPE_B: drink_B(x); break;
	TYPE_C: drink_C(x); break;
	}
}

void be_merry(X& x) {
	switch (x.get_type()) {
	TYPE_A: be_merry_A(x); break;
	TYPE_B: be_merry_B(x); break;
	TYPE_C: be_merry_C(x); break;
	}
}

class Base {
	virtual void eat() = 0;
	virtual void drink() = 0;
	virtual void be_merry() = 0;
	...
};

class A : public Base {
public:
	virtual void eat() { /* Eat A-specific stuff */ }
	virtual void drink() { /* Drink A-specific stuff */ }
	virtual void be_merry() { /* Be merry in an A-specific way */ }
};

class B : public Base {
public:
	virtual void eat() { /* Eat B-specific stuff */ }
	virtual void drink() { /* Drink B-specific stuff */ }
	virtual void be_merry() { /* Be merry in an B-specific way */ }
};

class C : public Base {
public:
	virtual void eat() { /* Eat C-specific stuff */ }
	virtual void drink() { /* Drink C-specific stuff */ }
	virtual void be_merry() { /* Be merry in a C-specific way */ }
};

/* Code Block 1... */

if(/* result of some condition or function call */)
{
   /* Code Block 2... */

   if(/* result of some condition or function call */)
   {
      /* Code Block 3... */

      if(/* result of some condition or function call */)
      {
         /* Code Block 4... */
      }
   }
}

/* Code Block 1... */
IsOk = /* result of some condition or function call */

if(IsOK)
{
   /* Code Block 2... */
   IsOk = /* result of some condition or function call */
}

if(IsOK)
{
   /* Code Block 3...*/
   IsOk = /* result of some condition or function call */
}

if(IsOK)
{
   /* Code Block 4...*/
   IsOk = /* result of some condition or function call */
}

/* And so on... */