CODEWITHSUNDEEP
c++
Korchkidu
Korchkidu

Reputation: 4946

When in-class member initialization is mandatory

When in-class member initialization is strictly mandatory?

Rules for in-class member initialization are complex and we could avoid that by using Ctor initializer list for non-static members and define static members outside the class. IMHO, this also separates declaration and definition more.

Upvotes: 1

Views: 129

Answers (1)

user743382
user743382

Reputation:

A static constant member must have an initialiser if it's used in-class in a context where a constant expression is required. For example,

struct S {
  static const int N = 4;
  int arr[N]; // okay
};

const int S::N;

struct T {
  static const int N;
  int arr[N]; // error
};

const int T::N = 4;

Upvotes: 3

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