This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 118f. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2025-11-07

2978. Deduction involving reference to similar types

(From submission #651.)

Consider:

  #include <cstddef>

  template <std::size_t N>
  void f(const int* const (&)[N]);

  int main() {
    int* a[3];
    f(a);
  }

There is implementation divergence.

Possible resolution:

Change in 13.10.3.2 [temp.deduct.call] bullet 4.1 as follows:

• If the original P is a reference type, the deduced A (i.e., the type referred to by the reference) can be more cv-qualified than a type similar to the transformed A that is reference-compatible with the transformed A.
• ...