MSVC fails to specialize template with `std::enable_if` and a non-type argument

This is a follow-up question to MSVC fails to deduce template argument

I am unable to find any combination that works on Visual Studio Enterprise 2019 (VS 16.11, MSVC 19.29). clang, g++ and MSVC 19.33 and later (without /permissive-) compile this code. MSVC 19.29 does not even if using /permissive-.

It looks a lot like a SFINAE bug.

#include <type_traits>

struct Prop1 {
  constexpr Prop1() {};
};
struct Prop2 {
  constexpr Prop2() {};
};

constexpr const Prop1 i;
constexpr const Prop2 j;

// the goal is that def() should have separate implementations
// for member variables and member functions
// (in my real code Prop1/Prop2 have default values, thus the enable_if
// is required, in the minimal repro this is not the case)
struct Klass {
  template <auto Klass::*MEMBER, const Prop2 &P,
    typename = std::enable_if_t<std::is_member_object_pointer_v<decltype(MEMBER)>>>
  void def() {}
  
  template <auto Klass::*MEMBER, const Prop1 &P,
    typename = std::enable_if_t<std::is_member_function_pointer_v<decltype(MEMBER)>>>
  void def() {}
  void fn();
  int var;
};

void Klass::fn() {}

int main() {
  Klass k;

  k.def<&Klass::fn, i>();
  k.def<&Klass::var, j>();
}

Demo

>Solution :

I am unable to find any combination that works on Visual Studio Enterprise 2019 (VS 16.11, MSVC 19.29)

Here is a workaround that uses SFINAE in the return type of the function template. This seems to be a msvc bug.

struct Klass {
  template <auto Klass::*MEMBER, const Prop2 &P>
//using SFINAE in the return type 
   typename std::enable_if_t<std::is_member_object_pointer_v<decltype(MEMBER)>> def() {}
  
  template <auto Klass::*MEMBER, const Prop1 &P>
//using SFINAE in the return type
  typename std::enable_if_t<std::is_member_function_pointer_v<decltype(MEMBER)>> def() {}
  void fn();
  int var;
};

Working demo