c++ - C++Niche Syntax: Function Reference Type Declaration: const reference? - Stack Overflow

This is a niche question, but I'm struggling to find a sufficient answer.

Struct members can be const, but can a function pointer/reference member be declared const? Based off my reading of C++17 section 9.3, I don't think so:

struct Ex {
  const int i;
  void (*pfn)(int i); // 1. can pfn be a const member?
  void (&rfn)(int i); // 2. can rfn be a const member?
};

This is a niche question, but I'm struggling to find a sufficient answer.

Struct members can be const, but can a function pointer/reference member be declared const? Based off my reading of C++17 section 9.3, I don't think so:

struct Ex {
  const int i;
  void (*pfn)(int i); // 1. can pfn be a const member?
  void (&rfn)(int i); // 2. can rfn be a const member?
};

• c++
• function-pointers
• function-reference

Share Improve this question Follow edited Jan 7 at 3:42 Remy Lebeau 602k3636 gold badges508508 silver badges854854 bronze badges asked Jan 6 at 22:02 JWCSJWCS 1,22111 gold badge99 silver badges2222 bronze badges 0

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1 Answer 1

Sorted by: Reset to default 5

1. Yes:

   struct Ex {
       const int i;
       void (*const pfn)(int i); // 1. can pfn be a const member?
       void (&rfn)(int i);       // 2. can rfn be a const member?
   };
   

2. It already is - You can't assign to a member referencing a function.