*Effective C++ 31. Minimize complilation dependencies between files(handle class & interface class)

最新推荐文章于 2020-10-01 15:31:54 发布

原创最新推荐文章于 2020-10-01 15:31:54 发布 · 275 阅读

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I. Handle classes

#include <string>
#include <memory>
class PersonImpl;
class Date;
class Address;

class Person {
public:
    Person(const std::string& name, const Date& birthday, const Address& addr);
    std::string name() const;
    std::string birthDate() const;
    std::string address() const;
private:
    std::tr1::shared_ptr<PersonImpl> pImpl;
};

#include "Person.h"
#include "PersonImpl.h"
class RealPerson;
Person::Person(const std::string& name, const Date& birthday, const Address& add): pImpl(new PersonImpl(name, birthday, addr)) { }
std::string Person::name const {
    return pImpl->name();
}

std::string Person::name() const {
    return pImpl->name();
}

clients use them like this

std::string name;
Date dateofBirth;
Address address;
Person pp(name, dataOfBirth, address);
std::cout << pp.name() << std::endl;

II. Interface classes

class Person {
public:
    virtual ~Person();
    virtual str::string name() const = 0;
    virtual std::string birthData() const = 0;
    virtual std::string address() const = 0;
    static std::tr1::shared_ptr<Person>
        create(const std::string& name, const Date& birthday, const Address& addr);
};
std::tr1::shared_ptr<Person> 
    Person::create(const std::string& name, const Date& birthday, const Address& addr) {
    return std::tr1::shared_ptr<Person> (new RealPerson(name, birthday, addr);
}

class RealPerson: public Person {
Public:
    RealPerson(const std::string& name, const Date& birthday, const Address& addr): theName(name), theBirthday(birthday), theAddress(addr) { }
    virtual ~RealPerson() { }
    std::string name() const;
    std::string birthDate() const;
    std::string address() const;
private:
    std::string theName;
    Date theBirthDate;
    Address theAddress;
};

clients use them like this

std::string name;
Date dateofBirth;
Address address;

std::tr1::shared_ptr<Person>pp (Person::create(name, dataOfBirth, address);

std::cout << pp->name() << std::endl;