[008]C/C++系列 | Class之間關係(二)-Delegation(委託)

// file String.hpp
class StringRep;
class String {
public:
    String();
    String(const char* s);
    String(const String& s);
    String &operator=(const String& s);
    ~String();
    ...
private:
    StringRep* rep; // pimpl
}

 

// file String.cpp
#include "String.hpp"
namespace {
class StringRep {
    friend class String;
    StringRep(const char* s);
    ~StringRep();
    int count;
    char* rep;
};
}

String::String(){...}