passobjectsbyref.cpp

来自「24学时攻克C++光盘源代码 深入浅出 方便实用」· C++ 代码 · 共 55 行

 //Listing 12.1
 // Passing pointers to objects
 #include <iostream>
 
 class SimpleCat
 {
 public:
     SimpleCat ();                    // constructor
     SimpleCat(SimpleCat&);     // copy constructor
     ~SimpleCat();                    // destructor
 };
 
 SimpleCat::SimpleCat()
 {
     std::cout << "Simple Cat Constructor...\n";
 }
 
 SimpleCat::SimpleCat(SimpleCat&)
 {
     std::cout << "Simple Cat Copy Constructor...\n";
 }
 
 SimpleCat::~SimpleCat()
 {
     std::cout << "Simple Cat Destructor...\n";
 }
 
 SimpleCat FunctionOne (SimpleCat theCat);
 SimpleCat* FunctionTwo (SimpleCat *theCat);
 
 int main()
 {
     std::cout << "Making a cat...\n";
     SimpleCat Frisky;
     std::cout << "Calling FunctionOne...\n";
     FunctionOne(Frisky);
     std::cout << "Calling FunctionTwo...\n";
     FunctionTwo(&Frisky);
     return 0;
 }
 
 // FunctionOne, passes by value
 SimpleCat FunctionOne(SimpleCat theCat)
 {
     std::cout << "Function One. Returning...\n";
     return theCat;
 }
 
 // functionTwo, passes by reference
 SimpleCat* FunctionTwo (SimpleCat  *theCat)
 {
     std::cout << "Function Two. Returning...\n";
     return theCat;
 }