Introduction

I.22: Avoid complex initialization of global objects

NOTE:

1、这其实就是Static-Initialization-Order-Fiasco，参见 Static-storage-duration 章节

I.4: Make interfaces precisely and strongly typed

NOTE:

1、参见 Strong-type 章节

T.83: Do not declare a member function template virtual

Reason

C++ does not support that. If it did, vtbls could not be generated until link time. And in general, implementations must deal with dynamic linking.

NOTE:

1、当前，virtual table是compile time生成的；如果支持template virtual function，那么virtual table需要直到link time才能够生成，并且还需要支持dynamic linking。

2、参见 Template-and-virtual 章节

Alternative

Double dispatch, visitors, calculate which function to call

T.84: Use a non-template core implementation to provide an ABI-stable interface

NOTE:

1、这其实就是在 Type-Erasure 章节中，总结的: "OOP interface + template implementation"

Example

It could be a base class:

struct Link_base {   // stable
    Link_base* suc;
    Link_base* pre;
};

template<typename T>   // templated wrapper to add type safety
struct Link : Link_base {
    T val;
};

struct List_base {
    Link_base* first;   // first element (if any)
    int sz;             // number of elements
    void add_front(Link_base* p);
    // ...
};

template<typename T>
class List : List_base {
public:
    void put_front(const T& e) { add_front(new Link<T>{e}); }   // implicit cast to Link_base
    T& front() { static_cast<Link<T>*>(first).val; }   // explicit cast back to Link<T>
    // ...
};C

List<int> li;
List<string> ls;

T.150: Check that a class matches a concept using static_assert

NOTE:

1、参见 static_assert 章节

SF.22: Use an unnamed (anonymous) namespace for all internal/non-exported entities

ES.20: Always initialize an object

NOTE:

1、Default-initialization:

对于built-in type，如果不对它进行initialization的话，那么它就是Indeterminate value，显然这是比较危险的；我们最好遵循

CppCoreGuidelines ES.20: Always initialize an object

Arithmetic

ES.100: Don't mix signed and unsigned arithmetic

NOTE:

1、在 pvs-studio About size_t and ptrdiff_t 中，有非常好的例子

ES.107: Don't use unsigned for subscripts, prefer gsl::index

NOTE:

1、参见 Array-index 章节

C.50: Use a factory function if you need "virtual behavior" during initialization

NOTE:

1、其实就是Calling-Virtual-During-Initialization-idiom

C.52: Use inheriting constructors to import constructors into a derived class that does not need further explicit initialization

NOTE:

C.copy: Copy and move