c++ - 结构成员的默认值

Question

(我确定这个问题已经得到回答，我只是不确定用正确的词来问它。如果有人能告诉我正确的术语是什么，那就太棒了!)

我正在用 C++ 为数据结构类实现一个 HashSet，我有一个关于结构的 C++ 语法的问题。这是我的代码:

struct HashNode
{
    T value;
    HashNode* next = nullptr;
};

当 new HashNode 被调用时，这段代码能正确地将 next 指针初始化为 nullptr 吗？如果不是，new HashNode 之后的next 的值是多少？

Answer 1

Will this code correctly initialize the next pointer to nullptr when new HashNode is called?

是的，它会被初始化为nullptr。这是 in-class brace-or-equal initializer (default member initializer) (C++11 起)，如果成员在成员初始化器列表中省略，则使用它。

Through a default member initializer, which is simply a brace or equals initializer included in the member declaration, which is used if the member is omitted in the member initializer list

If a member has a default member initializer and also appears in the member initialization list in a constructor, the default member initializer is ignored.