Why am I being asked to explicitly initialize a member when I have already created a constructor to do that?

Question

I'm trying to create a hashtable with chaining as the collision management method. I have a custom list to handle that. Here's the error I am running into:

error: constructor for 'Node' must explicitly initialize the member 'content' which does not have a default constructor

Constructor

  Node(const Y &content) {
    this->content = content;
    this->next = nullptr;
    this->prev = nullptr;
  }

Did you read the chapter in your C++ textbook that explains constructors' initialization sections, yet? What, specifically, in that chapter is unclear? — Sam Varshavchik, Dec 06 '22 at 13:28
@Jason And you perform member initialization with which syntax? ;-) — Peter - Reinstate Monica, Dec 06 '22 at 13:28

score 1 · Answer 1 · answered Dec 06 '22 at 13:28

Why am I being asked to explicitly initialize a member when I have already created a constructor to do that?

Because this->content = content; is assignment and not initialization. Before entering the constructor body, the content data member(and also others) will be default initialized. But since there is no default ctor for content, we get the mentioned error.

To solve this you can use member initializer list.

Node(const Y &content): content(content), next(nullptr), previous(nullptr)
{

}

Why am I being asked to explicitly initialize a member when I have already created a constructor to do that?

1 Answers1