Check if a function argument value is thread-local

In C++, is it possible to check (preferably at compile time) if a function argument reference value is thread-local?

E.g.

void foo( int& bar ) { ... }

I'd like to check/enforce that bar refer to a thread_local.

Assume C++17 or later on Windows and/or Fedora.

template<class T, auto Key>
struct thread_local_decl_t;

template<class T>
struct thread_local_t {
  template<class, auto>
  friend struct thread_local_decl_t;
  operator T&() noexcept {
    return get();
  }
  operator T const&() const noexcept {
    return get_const();
  }
private:
  T&(*gettor)() = nullptr;
  thread_local_t(T&(*gettor_arg)()):
    gettor(gettor_arg)
  {}
  T& get() { return gettor(); }
  T const& get_const() const { return gettor(); }
};
template<class T, auto Key>
struct thread_local_decl_t:
  thread_local_t<T>
{
public:
  static T& get_ctor(std::function<T()> ctor) {
    thread_local T t{ctor()};
    return t;
  }
  static T& get() {
    return get_ctor(nullptr);
  }
  static T const& get_const() {
    return get(nullptr);
  }
  template<class...Args>
  explicit thread_local_decl_t(Args&&...args):
    thread_local_t<T>(&thread_local_decl_t::get) 
  {
    // construct the thread-local
    get_ctor( [&]()->T{ return T(std::forward<Args>(args)...); } );
  }
  thread_local_decl_t(thread_local_decl_t const&)=default;
  thread_local_decl_t(thread_local_decl_t &&)=default;

};

#define THREAD_LOCAL(...) \
  thread_local_decl_t< __VA_ARGS__, []{} >


void print( thread_local_t<int> x ) {
  std::cout << x << "\n";
}

void test() {
  auto tl_int = THREAD_LOCAL(int)( 7 );
  print(tl_int);
}
int main() {
  test();
}

this bit of evil uses a lambda to create a thread local object within the thread_local_decl_t that is unique to each use site. We can pass thread local values around and verify they are indeed thread local with the C++ type system by doing a thread_local_t<int>.

thread_local_t<X> is a reference to a thread local value, while auto name = THREAD_LOCAL(X)(construction arguments) declares a thread local value, using this system.

Requires c++20.