4.11-const指针（复杂）.cpp

Visual C++的课件

//Listing 9.11
// Passing pointers to objects

#include <iostream.h>

class SimpleCat
{
public:
	SimpleCat();
	SimpleCat(SimpleCat&);
	~SimpleCat();

	int GetAge() const { return itsAge; }
	void SetAge(int age) { itsAge = age; }

private:
	int itsAge;
};

SimpleCat::SimpleCat()
{
	cout << "Simple Cat Constructor...\n";
	itsAge = 1;
}

SimpleCat::SimpleCat(SimpleCat&)
{
	cout << "Simple Cat Copy Constructor...\n";
}

SimpleCat::~SimpleCat()
{
	cout << "Simple Cat Destructor...\n";
}

const SimpleCat * const FunctionTwo (const SimpleCat * const theCat);

int main()
{
	cout << "Making a cat...\n";
	SimpleCat Frisky;
	cout << "Frisky is " ;
	cout << Frisky.GetAge();
	cout << " years old\n";
	int age = 5;
	Frisky.SetAge(age);
	cout << "Frisky is " ;
	cout << Frisky.GetAge();
	cout << " years old\n";
	cout << "Calling FunctionTwo...\n";
	FunctionTwo(&Frisky);
	cout << "Frisky is " ;
	cout << Frisky.GetAge();
	cout << " years old\n";
	return 0;
}

// functionTwo, passes a const pointer
const SimpleCat * const FunctionTwo (const SimpleCat * const theCat)
{
	cout << "Function Two. Returning...\n";
	cout << "Frisky is now " << theCat->GetAge();
	cout << " years old \n";
	// theCat->SetAge(8);   const!
	return theCat;
}