<Item 15> Provide access to raw resources in resource-managing classes 1.You need a way to convert an object of the RAII class (in this case, tr1::shared_ptr) into the raw resource it contains (e.g., the underlying Investment*). There are two genera…

1.除了内存资源以外,Other common resources include file descriptors, mutex locks, fonts and brushes in graphical user interfaces (GUIs), database connections, and network sockets. Regardless of the resource, it's important that it be released when you're fini…

<Item29> Strive for exception-safe code. 1.如下面的代码 class PrettyMenu { public: ... void changeBackground(std::istream& imgSrc); // change background ... // image private: Mutex mutex; // mutex for this object Image *bgImage; // current background…

<Item 18> Make interfaces easy to use correctly and hard to use incorrectly 1.That being the case, if they use one incorrectly, your interface is at least partially to blame. Ideally, if an attempted use of an interface won't do what the client expe…

<Item 36> Never redefine an inherited non-virtual function 1.如下代码通过不同指针调用同一个对象的同一个函数会产生不同的行为The reason for this two-faced behavior is that non-virtual functions like B::mf and D::mf are statically bound (see Item 37). That means that because pB is d…

<Item 20> Prefer pass-by-reference-to-const to pass-by-value 1.By default, C++ passes objects to and from functions by value (a characteristic it inherits from C). Unless you specify otherwise, function parameters are initialized with copies of the…

<Item 9> Never call virtual functions during construction or destruction 1.you shouldn't call virtual functions during construction or destruction, because the calls won't do what you think, and if they did, you'd still be unhappy. If you're a recov…

1.The initial motivation for C++ templates was straightforward: to make it possible to create type-safe containers like vector, list, and map. Ultimately, it was discovered that the C++ template mechanism is itself Turing-complete: it can be used to…

1.For the most part, coming up with appropriate definitions for your classes (and class templates) and appropriate declarations for your functions (and function templates) is the lion's share of the battle. Once you've got those right, the correspond…

<Item 22> Declare data members private 1.使数据成员private,保持了语法的一致性,client不会为访问一个数据成员是否需要使用括号进行函数调度,还是不使用括号直接访问成员而纠结. 2.使数据成员private,if you use functions to get or set its value, you can implement no access, read-only access, and read-write access. Heck…