//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef SUPPORT_TYPE_ID_H
#define SUPPORT_TYPE_ID_H

#include <functional>
#include <cassert>

#include "test_macros.h"

#if TEST_STD_VER < 11
#error This header requires C++11 or greater
#endif

// TypeID - Represent a unique identifier for a type. TypeID allows equality
// comparisons between different types.
struct TypeID {
  friend bool operator==(TypeID const& LHS, TypeID const& RHS)
  {return LHS.m_id == RHS.m_id; }
  friend bool operator!=(TypeID const& LHS, TypeID const& RHS)
  {return LHS.m_id != RHS.m_id; }
private:
  explicit constexpr TypeID(const int* xid) : m_id(xid) {}

  TypeID(const TypeID&) = delete;
  TypeID& operator=(TypeID const&) = delete;

  const int* const m_id;
  template <class T> friend TypeID const& makeTypeID();

};

// makeTypeID - Return the TypeID for the specified type 'T'.
template <class T>
inline TypeID const& makeTypeID() {
  static int dummy;
  static const TypeID id(&dummy);
  return id;
}

template <class ...Args>
struct ArgumentListID {};

// makeArgumentID - Create and return a unique identifier for a given set
// of arguments.
template <class ...Args>
inline  TypeID const& makeArgumentID() {
  return makeTypeID<ArgumentListID<Args...>>();
}

#endif // SUPPORT_TYPE_ID_H