// -*- C++ -*- header.
	
	// Copyright (C) 2008-2013 Free Software Foundation, Inc.
	//
	// This file is part of the GNU ISO C++ Library.  This library is free
	// software; you can redistribute it and/or modify it under the
	// terms of the GNU General Public License as published by the
	// Free Software Foundation; either version 3, or (at your option)
	// any later version.
	
	// This library is distributed in the hope that it will be useful,
	// but WITHOUT ANY WARRANTY; without even the implied warranty of
	// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	// GNU General Public License for more details.
	
	// Under Section 7 of GPL version 3, you are granted additional
	// permissions described in the GCC Runtime Library Exception, version
	// 3.1, as published by the Free Software Foundation.
	
	// You should have received a copy of the GNU General Public License and
	// a copy of the GCC Runtime Library Exception along with this program;
	// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
	// <http://www.gnu.org/licenses/>.
	
	/** @file include/atomic
	 *  This is a Standard C++ Library header.
	 */
	
	// Based on "C++ Atomic Types and Operations" by Hans Boehm and Lawrence Crowl.
	// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2427.html
	
	#ifndef _GLIBCXX_ATOMIC
	#define _GLIBCXX_ATOMIC 1
	
	#pragma GCC system_header
	
	#if __cplusplus < 201103L
	# include <bits/c++0x_warning.h>
	#endif
	
	#include <bits/atomic_base.h>
	
	namespace std _GLIBCXX_VISIBILITY(default)
	{
	_GLIBCXX_BEGIN_NAMESPACE_VERSION
	
	  /**
	   * @addtogroup atomics
	   * @{
	   */
	
	  /// atomic_bool
	  // NB: No operators or fetch-operations for this type.
	  struct atomic_bool
	  {
	  private:
	    __atomic_base<bool>	_M_base;
	
	  public:
	    atomic_bool() noexcept = default;
	    ~atomic_bool() noexcept = default;
	    atomic_bool(const atomic_bool&) = delete;
	    atomic_bool& operator=(const atomic_bool&) = delete;
	    atomic_bool& operator=(const atomic_bool&) volatile = delete;
	
	    constexpr atomic_bool(bool __i) noexcept : _M_base(__i) { }
	
	    bool
	    operator=(bool __i) noexcept
	    { return _M_base.operator=(__i); }
	
	    bool
	    operator=(bool __i) volatile noexcept
	    { return _M_base.operator=(__i); }
	
	    operator bool() const noexcept
	    { return _M_base.load(); }
	
	    operator bool() const volatile noexcept
	    { return _M_base.load(); }
	
	    bool
	    is_lock_free() const noexcept { return _M_base.is_lock_free(); }
	
	    bool
	    is_lock_free() const volatile noexcept { return _M_base.is_lock_free(); }
	
	    void
	    store(bool __i, memory_order __m = memory_order_seq_cst) noexcept
	    { _M_base.store(__i, __m); }
	
	    void
	    store(bool __i, memory_order __m = memory_order_seq_cst) volatile noexcept
	    { _M_base.store(__i, __m); }
	
	    bool
	    load(memory_order __m = memory_order_seq_cst) const noexcept
	    { return _M_base.load(__m); }
	
	    bool
	    load(memory_order __m = memory_order_seq_cst) const volatile noexcept
	    { return _M_base.load(__m); }
	
	    bool
	    exchange(bool __i, memory_order __m = memory_order_seq_cst) noexcept
	    { return _M_base.exchange(__i, __m); }
	
	    bool
	    exchange(bool __i,
		     memory_order __m = memory_order_seq_cst) volatile noexcept
	    { return _M_base.exchange(__i, __m); }
	
	    bool
	    compare_exchange_weak(bool& __i1, bool __i2, memory_order __m1,
				  memory_order __m2) noexcept
	    { return _M_base.compare_exchange_weak(__i1, __i2, __m1, __m2); }
	
	    bool
	    compare_exchange_weak(bool& __i1, bool __i2, memory_order __m1,
				  memory_order __m2) volatile noexcept
	    { return _M_base.compare_exchange_weak(__i1, __i2, __m1, __m2); }
	
	    bool
	    compare_exchange_weak(bool& __i1, bool __i2,
				  memory_order __m = memory_order_seq_cst) noexcept
	    { return _M_base.compare_exchange_weak(__i1, __i2, __m); }
	
	    bool
	    compare_exchange_weak(bool& __i1, bool __i2,
			     memory_order __m = memory_order_seq_cst) volatile noexcept
	    { return _M_base.compare_exchange_weak(__i1, __i2, __m); }
	
	    bool
	    compare_exchange_strong(bool& __i1, bool __i2, memory_order __m1,
				    memory_order __m2) noexcept
	    { return _M_base.compare_exchange_strong(__i1, __i2, __m1, __m2); }
	
	    bool
	    compare_exchange_strong(bool& __i1, bool __i2, memory_order __m1,
				    memory_order __m2) volatile noexcept
	    { return _M_base.compare_exchange_strong(__i1, __i2, __m1, __m2); }
	
	    bool
	    compare_exchange_strong(bool& __i1, bool __i2,
				    memory_order __m = memory_order_seq_cst) noexcept
	    { return _M_base.compare_exchange_strong(__i1, __i2, __m); }
	
	    bool
	    compare_exchange_strong(bool& __i1, bool __i2,
			    memory_order __m = memory_order_seq_cst) volatile noexcept
	    { return _M_base.compare_exchange_strong(__i1, __i2, __m); }
	  };
	
	
	  /**
	   *  @brief Generic atomic type, primary class template.
	   *
	   *  @tparam _Tp  Type to be made atomic, must be trivally copyable.
	   */
	  template<typename _Tp>
	    struct atomic
	    {
	    private:
	      _Tp _M_i;
	
	    public:
	      atomic() noexcept = default;
	      ~atomic() noexcept = default;
	      atomic(const atomic&) = delete;
	      atomic& operator=(const atomic&) = delete;
	      atomic& operator=(const atomic&) volatile = delete;
	
	      constexpr atomic(_Tp __i) noexcept : _M_i(__i) { }
	
	      operator _Tp() const noexcept
	      { return load(); }
	
	      operator _Tp() const volatile noexcept
	      { return load(); }
	
	      _Tp
	      operator=(_Tp __i) noexcept 
	      { store(__i); return __i; }
	
	      _Tp
	      operator=(_Tp __i) volatile noexcept 
	      { store(__i); return __i; }
	
	      bool
	      is_lock_free() const noexcept
	      { return __atomic_is_lock_free(sizeof(_M_i), nullptr); }
	
	      bool
	      is_lock_free() const volatile noexcept
	      { return __atomic_is_lock_free(sizeof(_M_i), nullptr); }
	
	      void
	      store(_Tp __i, memory_order _m = memory_order_seq_cst) noexcept
	      { __atomic_store(&_M_i, &__i, _m); }
	
	      void
	      store(_Tp __i, memory_order _m = memory_order_seq_cst) volatile noexcept
	      { __atomic_store(&_M_i, &__i, _m); }
	
	      _Tp
	      load(memory_order _m = memory_order_seq_cst) const noexcept
	      { 
	        _Tp tmp;
		__atomic_load(&_M_i, &tmp, _m); 
		return tmp;
	      }
	
	      _Tp
	      load(memory_order _m = memory_order_seq_cst) const volatile noexcept
	      { 
	        _Tp tmp;
		__atomic_load(&_M_i, &tmp, _m); 
		return tmp;
	      }
	
	      _Tp
	      exchange(_Tp __i, memory_order _m = memory_order_seq_cst) noexcept
	      { 
	        _Tp tmp;
		__atomic_exchange(&_M_i, &__i, &tmp, _m); 
		return tmp;
	      }
	
	      _Tp
	      exchange(_Tp __i, 
		       memory_order _m = memory_order_seq_cst) volatile noexcept
	      { 
	        _Tp tmp;
		__atomic_exchange(&_M_i, &__i, &tmp, _m); 
		return tmp;
	      }
	
	      bool
	      compare_exchange_weak(_Tp& __e, _Tp __i, memory_order __s, 
				    memory_order __f) noexcept
	      {
		return __atomic_compare_exchange(&_M_i, &__e, &__i, true, __s, __f); 
	      }
	
	      bool
	      compare_exchange_weak(_Tp& __e, _Tp __i, memory_order __s, 
				    memory_order __f) volatile noexcept
	      {
		return __atomic_compare_exchange(&_M_i, &__e, &__i, true, __s, __f); 
	      }
	
	      bool
	      compare_exchange_weak(_Tp& __e, _Tp __i,
				    memory_order __m = memory_order_seq_cst) noexcept
	      { return compare_exchange_weak(__e, __i, __m, __m); }
	
	      bool
	      compare_exchange_weak(_Tp& __e, _Tp __i,
			     memory_order __m = memory_order_seq_cst) volatile noexcept
	      { return compare_exchange_weak(__e, __i, __m, __m); }
	
	      bool
	      compare_exchange_strong(_Tp& __e, _Tp __i, memory_order __s, 
				      memory_order __f) noexcept
	      {
		return __atomic_compare_exchange(&_M_i, &__e, &__i, false, __s, __f); 
	      }
	
	      bool
	      compare_exchange_strong(_Tp& __e, _Tp __i, memory_order __s, 
				      memory_order __f) volatile noexcept
	      {
		return __atomic_compare_exchange(&_M_i, &__e, &__i, false, __s, __f); 
	      }
	
	      bool
	      compare_exchange_strong(_Tp& __e, _Tp __i,
				       memory_order __m = memory_order_seq_cst) noexcept
	      { return compare_exchange_strong(__e, __i, __m, __m); }
	
	      bool
	      compare_exchange_strong(_Tp& __e, _Tp __i,
			     memory_order __m = memory_order_seq_cst) volatile noexcept
	      { return compare_exchange_strong(__e, __i, __m, __m); }
	    };
	
	
	  /// Partial specialization for pointer types.
	  template<typename _Tp>
	    struct atomic<_Tp*>
	    {
	      typedef _Tp* 			__pointer_type;
	      typedef __atomic_base<_Tp*>	__base_type;
	      __base_type			_M_b;
	
	      atomic() noexcept = default;
	      ~atomic() noexcept = default;
	      atomic(const atomic&) = delete;
	      atomic& operator=(const atomic&) = delete;
	      atomic& operator=(const atomic&) volatile = delete;
	
	      constexpr atomic(__pointer_type __p) noexcept : _M_b(__p) { }
	
	      operator __pointer_type() const noexcept
	      { return __pointer_type(_M_b); }
	
	      operator __pointer_type() const volatile noexcept
	      { return __pointer_type(_M_b); }
	
	      __pointer_type
	      operator=(__pointer_type __p) noexcept
	      { return _M_b.operator=(__p); }
	
	      __pointer_type
	      operator=(__pointer_type __p) volatile noexcept
	      { return _M_b.operator=(__p); }
	
	      __pointer_type
	      operator++(int) noexcept
	      { return _M_b++; }
	
	      __pointer_type
	      operator++(int) volatile noexcept
	      { return _M_b++; }
	
	      __pointer_type
	      operator--(int) noexcept
	      { return _M_b--; }
	
	      __pointer_type
	      operator--(int) volatile noexcept
	      { return _M_b--; }
	
	      __pointer_type
	      operator++() noexcept
	      { return ++_M_b; }
	
	      __pointer_type
	      operator++() volatile noexcept
	      { return ++_M_b; }
	
	      __pointer_type
	      operator--() noexcept
	      { return --_M_b; }
	
	      __pointer_type
	      operator--() volatile noexcept
	      { return --_M_b; }
	
	      __pointer_type
	      operator+=(ptrdiff_t __d) noexcept
	      { return _M_b.operator+=(__d); }
	
	      __pointer_type
	      operator+=(ptrdiff_t __d) volatile noexcept
	      { return _M_b.operator+=(__d); }
	
	      __pointer_type
	      operator-=(ptrdiff_t __d) noexcept
	      { return _M_b.operator-=(__d); }
	
	      __pointer_type
	      operator-=(ptrdiff_t __d) volatile noexcept
	      { return _M_b.operator-=(__d); }
	
	      bool
	      is_lock_free() const noexcept
	      { return _M_b.is_lock_free(); }
	
	      bool
	      is_lock_free() const volatile noexcept
	      { return _M_b.is_lock_free(); }
	
	      void
	      store(__pointer_type __p,
		    memory_order __m = memory_order_seq_cst) noexcept
	      { return _M_b.store(__p, __m); }
	
	      void
	      store(__pointer_type __p,
		    memory_order __m = memory_order_seq_cst) volatile noexcept
	      { return _M_b.store(__p, __m); }
	
	      __pointer_type
	      load(memory_order __m = memory_order_seq_cst) const noexcept
	      { return _M_b.load(__m); }
	
	      __pointer_type
	      load(memory_order __m = memory_order_seq_cst) const volatile noexcept
	      { return _M_b.load(__m); }
	
	      __pointer_type
	      exchange(__pointer_type __p,
		       memory_order __m = memory_order_seq_cst) noexcept
	      { return _M_b.exchange(__p, __m); }
	
	      __pointer_type
	      exchange(__pointer_type __p,
		       memory_order __m = memory_order_seq_cst) volatile noexcept
	      { return _M_b.exchange(__p, __m); }
	
	      bool
	      compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
				    memory_order __m1, memory_order __m2) noexcept
	      { return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }
	
	      bool
	      compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
				    memory_order __m1,
				    memory_order __m2) volatile noexcept
	      { return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }
	
	      bool
	      compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
				    memory_order __m = memory_order_seq_cst) noexcept
	      {
		return compare_exchange_weak(__p1, __p2, __m,
					     __cmpexch_failure_order(__m));
	      }
	
	      bool
	      compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
			    memory_order __m = memory_order_seq_cst) volatile noexcept
	      {
		return compare_exchange_weak(__p1, __p2, __m,
					     __cmpexch_failure_order(__m));
	      }
	
	      bool
	      compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
				      memory_order __m1, memory_order __m2) noexcept
	      { return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }
	
	      bool
	      compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
				      memory_order __m1,
				      memory_order __m2) volatile noexcept
	      { return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }
	
	      bool
	      compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
				      memory_order __m = memory_order_seq_cst) noexcept
	      {
		return _M_b.compare_exchange_strong(__p1, __p2, __m,
						    __cmpexch_failure_order(__m));
	      }
	
	      bool
	      compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
			    memory_order __m = memory_order_seq_cst) volatile noexcept
	      {
		return _M_b.compare_exchange_strong(__p1, __p2, __m,
						    __cmpexch_failure_order(__m));
	      }
	
	      __pointer_type
	      fetch_add(ptrdiff_t __d,
			memory_order __m = memory_order_seq_cst) noexcept
	      { return _M_b.fetch_add(__d, __m); }
	
	      __pointer_type
	      fetch_add(ptrdiff_t __d,
			memory_order __m = memory_order_seq_cst) volatile noexcept
	      { return _M_b.fetch_add(__d, __m); }
	
	      __pointer_type
	      fetch_sub(ptrdiff_t __d,
			memory_order __m = memory_order_seq_cst) noexcept
	      { return _M_b.fetch_sub(__d, __m); }
	
	      __pointer_type
	      fetch_sub(ptrdiff_t __d,
			memory_order __m = memory_order_seq_cst) volatile noexcept
	      { return _M_b.fetch_sub(__d, __m); }
	    };
	
	
	  /// Explicit specialization for bool.
	  template<>
	    struct atomic<bool> : public atomic_bool
	    {
	      typedef bool 			__integral_type;
	      typedef atomic_bool 		__base_type;
	
	      atomic() noexcept = default;
	      ~atomic() noexcept = default;
	      atomic(const atomic&) = delete;
	      atomic& operator=(const atomic&) = delete;
	      atomic& operator=(const atomic&) volatile = delete;
	
	      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
	
	      using __base_type::operator __integral_type;
	      using __base_type::operator=;
	    };
	
	  /// Explicit specialization for char.
	  template<>
	    struct atomic<char> : public atomic_char
	    {
	      typedef char 			__integral_type;
	      typedef atomic_char 		__base_type;
	
	      atomic() noexcept = default;
	      ~atomic() noexcept = default;
	      atomic(const atomic&) = delete;
	      atomic& operator=(const atomic&) = delete;
	      atomic& operator=(const atomic&) volatile = delete;
	
	      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
	
	      using __base_type::operator __integral_type;
	      using __base_type::operator=;
	    };
	
	  /// Explicit specialization for signed char.
	  template<>
	    struct atomic<signed char> : public atomic_schar
	    {
	      typedef signed char 		__integral_type;
	      typedef atomic_schar 		__base_type;
	
	      atomic() noexcept= default;
	      ~atomic() noexcept = default;
	      atomic(const atomic&) = delete;
	      atomic& operator=(const atomic&) = delete;
	      atomic& operator=(const atomic&) volatile = delete;
	
	      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
	
	      using __base_type::operator __integral_type;
	      using __base_type::operator=;
	    };
	
	  /// Explicit specialization for unsigned char.
	  template<>
	    struct atomic<unsigned char> : public atomic_uchar
	    {
	      typedef unsigned char 		__integral_type;
	      typedef atomic_uchar 		__base_type;
	
	      atomic() noexcept= default;
	      ~atomic() noexcept = default;
	      atomic(const atomic&) = delete;
	      atomic& operator=(const atomic&) = delete;
	      atomic& operator=(const atomic&) volatile = delete;
	
	      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
	
	      using __base_type::operator __integral_type;
	      using __base_type::operator=;
	    };
	
	  /// Explicit specialization for short.
	  template<>
	    struct atomic<short> : public atomic_short
	    {
	      typedef short 			__integral_type;
	      typedef atomic_short 		__base_type;
	
	      atomic() noexcept = default;
	      ~atomic() noexcept = default;
	      atomic(const atomic&) = delete;
	      atomic& operator=(const atomic&) = delete;
	      atomic& operator=(const atomic&) volatile = delete;
	
	      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
	
	      using __base_type::operator __integral_type;
	      using __base_type::operator=;
	    };
	
	  /// Explicit specialization for unsigned short.
	  template<>
	    struct atomic<unsigned short> : public atomic_ushort
	    {
	      typedef unsigned short 	      	__integral_type;
	      typedef atomic_ushort 		__base_type;
	
	      atomic() noexcept = default;
	      ~atomic() noexcept = default;
	      atomic(const atomic&) = delete;
	      atomic& operator=(const atomic&) = delete;
	      atomic& operator=(const atomic&) volatile = delete;
	
	      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
	
	      using __base_type::operator __integral_type;
	      using __base_type::operator=;
	    };
	
	  /// Explicit specialization for int.
	  template<>
	    struct atomic<int> : atomic_int
	    {
	      typedef int 			__integral_type;
	      typedef atomic_int 		__base_type;
	
	      atomic() noexcept = default;
	      ~atomic() noexcept = default;
	      atomic(const atomic&) = delete;
	      atomic& operator=(const atomic&) = delete;
	      atomic& operator=(const atomic&) volatile = delete;
	
	      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
	
	      using __base_type::operator __integral_type;
	      using __base_type::operator=;
	    };
	
	  /// Explicit specialization for unsigned int.
	  template<>
	    struct atomic<unsigned int> : public atomic_uint
	    {
	      typedef unsigned int		__integral_type;
	      typedef atomic_uint 		__base_type;
	
	      atomic() noexcept = default;
	      ~atomic() noexcept = default;
	      atomic(const atomic&) = delete;
	      atomic& operator=(const atomic&) = delete;
	      atomic& operator=(const atomic&) volatile = delete;
	
	      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
	
	      using __base_type::operator __integral_type;
	      using __base_type::operator=;
	    };
	
	  /// Explicit specialization for long.
	  template<>
	    struct atomic<long> : public atomic_long
	    {
	      typedef long 			__integral_type;
	      typedef atomic_long 		__base_type;
	
	      atomic() noexcept = default;
	      ~atomic() noexcept = default;
	      atomic(const atomic&) = delete;
	      atomic& operator=(const atomic&) = delete;
	      atomic& operator=(const atomic&) volatile = delete;
	
	      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
	
	      using __base_type::operator __integral_type;
	      using __base_type::operator=;
	    };
	
	  /// Explicit specialization for unsigned long.
	  template<>
	    struct atomic<unsigned long> : public atomic_ulong
	    {
	      typedef unsigned long 		__integral_type;
	      typedef atomic_ulong 		__base_type;
	
	      atomic() noexcept = default;
	      ~atomic() noexcept = default;
	      atomic(const atomic&) = delete;
	      atomic& operator=(const atomic&) = delete;
	      atomic& operator=(const atomic&) volatile = delete;
	
	      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
	
	      using __base_type::operator __integral_type;
	      using __base_type::operator=;
	    };
	
	  /// Explicit specialization for long long.
	  template<>
	    struct atomic<long long> : public atomic_llong
	    {
	      typedef long long 		__integral_type;
	      typedef atomic_llong 		__base_type;
	
	      atomic() noexcept = default;
	      ~atomic() noexcept = default;
	      atomic(const atomic&) = delete;
	      atomic& operator=(const atomic&) = delete;
	      atomic& operator=(const atomic&) volatile = delete;
	
	      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
	
	      using __base_type::operator __integral_type;
	      using __base_type::operator=;
	    };
	
	  /// Explicit specialization for unsigned long long.
	  template<>
	    struct atomic<unsigned long long> : public atomic_ullong
	    {
	      typedef unsigned long long       	__integral_type;
	      typedef atomic_ullong 		__base_type;
	
	      atomic() noexcept = default;
	      ~atomic() noexcept = default;
	      atomic(const atomic&) = delete;
	      atomic& operator=(const atomic&) = delete;
	      atomic& operator=(const atomic&) volatile = delete;
	
	      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
	
	      using __base_type::operator __integral_type;
	      using __base_type::operator=;
	    };
	
	  /// Explicit specialization for wchar_t.
	  template<>
	    struct atomic<wchar_t> : public atomic_wchar_t
	    {
	      typedef wchar_t 			__integral_type;
	      typedef atomic_wchar_t 		__base_type;
	
	      atomic() noexcept = default;
	      ~atomic() noexcept = default;
	      atomic(const atomic&) = delete;
	      atomic& operator=(const atomic&) = delete;
	      atomic& operator=(const atomic&) volatile = delete;
	
	      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
	
	      using __base_type::operator __integral_type;
	      using __base_type::operator=;
	    };
	
	  /// Explicit specialization for char16_t.
	  template<>
	    struct atomic<char16_t> : public atomic_char16_t
	    {
	      typedef char16_t 			__integral_type;
	      typedef atomic_char16_t 		__base_type;
	
	      atomic() noexcept = default;
	      ~atomic() noexcept = default;
	      atomic(const atomic&) = delete;
	      atomic& operator=(const atomic&) = delete;
	      atomic& operator=(const atomic&) volatile = delete;
	
	      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
	
	      using __base_type::operator __integral_type;
	      using __base_type::operator=;
	    };
	
	  /// Explicit specialization for char32_t.
	  template<>
	    struct atomic<char32_t> : public atomic_char32_t
	    {
	      typedef char32_t 			__integral_type;
	      typedef atomic_char32_t 		__base_type;
	
	      atomic() noexcept = default;
	      ~atomic() noexcept = default;
	      atomic(const atomic&) = delete;
	      atomic& operator=(const atomic&) = delete;
	      atomic& operator=(const atomic&) volatile = delete;
	
	      constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
	
	      using __base_type::operator __integral_type;
	      using __base_type::operator=;
	    };
	
	
	  // Function definitions, atomic_flag operations.
	  inline bool
	  atomic_flag_test_and_set_explicit(atomic_flag* __a,
					    memory_order __m) noexcept
	  { return __a->test_and_set(__m); }
	
	  inline bool
	  atomic_flag_test_and_set_explicit(volatile atomic_flag* __a,
					    memory_order __m) noexcept
	  { return __a->test_and_set(__m); }
	
	  inline void
	  atomic_flag_clear_explicit(atomic_flag* __a, memory_order __m) noexcept
	  { __a->clear(__m); }
	
	  inline void
	  atomic_flag_clear_explicit(volatile atomic_flag* __a,
				     memory_order __m) noexcept
	  { __a->clear(__m); }
	
	  inline bool
	  atomic_flag_test_and_set(atomic_flag* __a) noexcept
	  { return atomic_flag_test_and_set_explicit(__a, memory_order_seq_cst); }
	
	  inline bool
	  atomic_flag_test_and_set(volatile atomic_flag* __a) noexcept
	  { return atomic_flag_test_and_set_explicit(__a, memory_order_seq_cst); }
	
	  inline void
	  atomic_flag_clear(atomic_flag* __a) noexcept
	  { atomic_flag_clear_explicit(__a, memory_order_seq_cst); }
	
	  inline void
	  atomic_flag_clear(volatile atomic_flag* __a) noexcept
	  { atomic_flag_clear_explicit(__a, memory_order_seq_cst); }
	
	
	  // Function templates generally applicable to atomic types.
	  template<typename _ITp>
	    inline bool
	    atomic_is_lock_free(const atomic<_ITp>* __a) noexcept
	    { return __a->is_lock_free(); }
	
	  template<typename _ITp>
	    inline bool
	    atomic_is_lock_free(const volatile atomic<_ITp>* __a) noexcept
	    { return __a->is_lock_free(); }
	
	  template<typename _ITp>
	    inline void
	    atomic_init(atomic<_ITp>* __a, _ITp __i) noexcept;
	
	  template<typename _ITp>
	    inline void
	    atomic_init(volatile atomic<_ITp>* __a, _ITp __i) noexcept;
	
	  template<typename _ITp>
	    inline void
	    atomic_store_explicit(atomic<_ITp>* __a, _ITp __i,
				  memory_order __m) noexcept
	    { __a->store(__i, __m); }
	
	  template<typename _ITp>
	    inline void
	    atomic_store_explicit(volatile atomic<_ITp>* __a, _ITp __i,
				  memory_order __m) noexcept
	    { __a->store(__i, __m); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_load_explicit(const atomic<_ITp>* __a, memory_order __m) noexcept
	    { return __a->load(__m); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_load_explicit(const volatile atomic<_ITp>* __a,
				 memory_order __m) noexcept
	    { return __a->load(__m); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_exchange_explicit(atomic<_ITp>* __a, _ITp __i,
				     memory_order __m) noexcept
	    { return __a->exchange(__i, __m); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_exchange_explicit(volatile atomic<_ITp>* __a, _ITp __i,
				     memory_order __m) noexcept
	    { return __a->exchange(__i, __m); }
	
	  template<typename _ITp>
	    inline bool
	    atomic_compare_exchange_weak_explicit(atomic<_ITp>* __a,
						  _ITp* __i1, _ITp __i2,
						  memory_order __m1,
						  memory_order __m2) noexcept
	    { return __a->compare_exchange_weak(*__i1, __i2, __m1, __m2); }
	
	  template<typename _ITp>
	    inline bool
	    atomic_compare_exchange_weak_explicit(volatile atomic<_ITp>* __a,
						  _ITp* __i1, _ITp __i2,
						  memory_order __m1,
						  memory_order __m2) noexcept
	    { return __a->compare_exchange_weak(*__i1, __i2, __m1, __m2); }
	
	  template<typename _ITp>
	    inline bool
	    atomic_compare_exchange_strong_explicit(atomic<_ITp>* __a,
						    _ITp* __i1, _ITp __i2,
						    memory_order __m1,
						    memory_order __m2) noexcept
	    { return __a->compare_exchange_strong(*__i1, __i2, __m1, __m2); }
	
	  template<typename _ITp>
	    inline bool
	    atomic_compare_exchange_strong_explicit(volatile atomic<_ITp>* __a,
						    _ITp* __i1, _ITp __i2,
						    memory_order __m1,
						    memory_order __m2) noexcept
	    { return __a->compare_exchange_strong(*__i1, __i2, __m1, __m2); }
	
	
	  template<typename _ITp>
	    inline void
	    atomic_store(atomic<_ITp>* __a, _ITp __i) noexcept
	    { atomic_store_explicit(__a, __i, memory_order_seq_cst); }
	
	  template<typename _ITp>
	    inline void
	    atomic_store(volatile atomic<_ITp>* __a, _ITp __i) noexcept
	    { atomic_store_explicit(__a, __i, memory_order_seq_cst); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_load(const atomic<_ITp>* __a) noexcept
	    { return atomic_load_explicit(__a, memory_order_seq_cst); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_load(const volatile atomic<_ITp>* __a) noexcept
	    { return atomic_load_explicit(__a, memory_order_seq_cst); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_exchange(atomic<_ITp>* __a, _ITp __i) noexcept
	    { return atomic_exchange_explicit(__a, __i, memory_order_seq_cst); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_exchange(volatile atomic<_ITp>* __a, _ITp __i) noexcept
	    { return atomic_exchange_explicit(__a, __i, memory_order_seq_cst); }
	
	  template<typename _ITp>
	    inline bool
	    atomic_compare_exchange_weak(atomic<_ITp>* __a,
					 _ITp* __i1, _ITp __i2) noexcept
	    {
	      return atomic_compare_exchange_weak_explicit(__a, __i1, __i2,
							   memory_order_seq_cst,
							   memory_order_seq_cst);
	    }
	
	  template<typename _ITp>
	    inline bool
	    atomic_compare_exchange_weak(volatile atomic<_ITp>* __a,
					 _ITp* __i1, _ITp __i2) noexcept
	    {
	      return atomic_compare_exchange_weak_explicit(__a, __i1, __i2,
							   memory_order_seq_cst,
							   memory_order_seq_cst);
	    }
	
	  template<typename _ITp>
	    inline bool
	    atomic_compare_exchange_strong(atomic<_ITp>* __a,
					   _ITp* __i1, _ITp __i2) noexcept
	    {
	      return atomic_compare_exchange_strong_explicit(__a, __i1, __i2,
							     memory_order_seq_cst,
							     memory_order_seq_cst);
	    }
	
	  template<typename _ITp>
	    inline bool
	    atomic_compare_exchange_strong(volatile atomic<_ITp>* __a,
					   _ITp* __i1, _ITp __i2) noexcept
	    {
	      return atomic_compare_exchange_strong_explicit(__a, __i1, __i2,
							     memory_order_seq_cst,
							     memory_order_seq_cst);
	    }
	
	  // Function templates for atomic_integral operations only, using
	  // __atomic_base. Template argument should be constricted to
	  // intergral types as specified in the standard, excluding address
	  // types.
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_add_explicit(__atomic_base<_ITp>* __a, _ITp __i,
				      memory_order __m) noexcept
	    { return __a->fetch_add(__i, __m); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_add_explicit(volatile __atomic_base<_ITp>* __a, _ITp __i,
				      memory_order __m) noexcept
	    { return __a->fetch_add(__i, __m); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_sub_explicit(__atomic_base<_ITp>* __a, _ITp __i,
				      memory_order __m) noexcept
	    { return __a->fetch_sub(__i, __m); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_sub_explicit(volatile __atomic_base<_ITp>* __a, _ITp __i,
				      memory_order __m) noexcept
	    { return __a->fetch_sub(__i, __m); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_and_explicit(__atomic_base<_ITp>* __a, _ITp __i,
				      memory_order __m) noexcept
	    { return __a->fetch_and(__i, __m); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_and_explicit(volatile __atomic_base<_ITp>* __a, _ITp __i,
				      memory_order __m) noexcept
	    { return __a->fetch_and(__i, __m); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_or_explicit(__atomic_base<_ITp>* __a, _ITp __i,
				     memory_order __m) noexcept
	    { return __a->fetch_or(__i, __m); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_or_explicit(volatile __atomic_base<_ITp>* __a, _ITp __i,
				     memory_order __m) noexcept
	    { return __a->fetch_or(__i, __m); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_xor_explicit(__atomic_base<_ITp>* __a, _ITp __i,
				      memory_order __m) noexcept
	    { return __a->fetch_xor(__i, __m); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_xor_explicit(volatile __atomic_base<_ITp>* __a, _ITp __i,
				      memory_order __m) noexcept
	    { return __a->fetch_xor(__i, __m); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_add(__atomic_base<_ITp>* __a, _ITp __i) noexcept
	    { return atomic_fetch_add_explicit(__a, __i, memory_order_seq_cst); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_add(volatile __atomic_base<_ITp>* __a, _ITp __i) noexcept
	    { return atomic_fetch_add_explicit(__a, __i, memory_order_seq_cst); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_sub(__atomic_base<_ITp>* __a, _ITp __i) noexcept
	    { return atomic_fetch_sub_explicit(__a, __i, memory_order_seq_cst); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_sub(volatile __atomic_base<_ITp>* __a, _ITp __i) noexcept
	    { return atomic_fetch_sub_explicit(__a, __i, memory_order_seq_cst); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_and(__atomic_base<_ITp>* __a, _ITp __i) noexcept
	    { return atomic_fetch_and_explicit(__a, __i, memory_order_seq_cst); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_and(volatile __atomic_base<_ITp>* __a, _ITp __i) noexcept
	    { return atomic_fetch_and_explicit(__a, __i, memory_order_seq_cst); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_or(__atomic_base<_ITp>* __a, _ITp __i) noexcept
	    { return atomic_fetch_or_explicit(__a, __i, memory_order_seq_cst); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_or(volatile __atomic_base<_ITp>* __a, _ITp __i) noexcept
	    { return atomic_fetch_or_explicit(__a, __i, memory_order_seq_cst); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_xor(__atomic_base<_ITp>* __a, _ITp __i) noexcept
	    { return atomic_fetch_xor_explicit(__a, __i, memory_order_seq_cst); }
	
	  template<typename _ITp>
	    inline _ITp
	    atomic_fetch_xor(volatile __atomic_base<_ITp>* __a, _ITp __i) noexcept
	    { return atomic_fetch_xor_explicit(__a, __i, memory_order_seq_cst); }
	
	
	  // Partial specializations for pointers.
	  template<typename _ITp>
	    inline _ITp*
	    atomic_fetch_add_explicit(atomic<_ITp*>* __a, ptrdiff_t __d,
				      memory_order __m) noexcept
	    { return __a->fetch_add(__d, __m); }
	
	  template<typename _ITp>
	    inline _ITp*
	    atomic_fetch_add_explicit(volatile atomic<_ITp*>* __a, ptrdiff_t __d,
				      memory_order __m) noexcept
	    { return __a->fetch_add(__d, __m); }
	
	  template<typename _ITp>
	    inline _ITp*
	    atomic_fetch_add(volatile atomic<_ITp*>* __a, ptrdiff_t __d) noexcept
	    { return __a->fetch_add(__d); }
	
	  template<typename _ITp>
	    inline _ITp*
	    atomic_fetch_add(atomic<_ITp*>* __a, ptrdiff_t __d) noexcept
	    { return __a->fetch_add(__d); }
	
	  template<typename _ITp>
	    inline _ITp*
	    atomic_fetch_sub_explicit(volatile atomic<_ITp*>* __a,
				      ptrdiff_t __d, memory_order __m) noexcept
	    { return __a->fetch_sub(__d, __m); }
	
	  template<typename _ITp>
	    inline _ITp*
	    atomic_fetch_sub_explicit(atomic<_ITp*>* __a, ptrdiff_t __d,
				      memory_order __m) noexcept
	    { return __a->fetch_sub(__d, __m); }
	
	  template<typename _ITp>
	    inline _ITp*
	    atomic_fetch_sub(volatile atomic<_ITp*>* __a, ptrdiff_t __d) noexcept
	    { return __a->fetch_sub(__d); }
	
	  template<typename _ITp>
	    inline _ITp*
	    atomic_fetch_sub(atomic<_ITp*>* __a, ptrdiff_t __d) noexcept
	    { return __a->fetch_sub(__d); }
	  // @} group atomics
	
	_GLIBCXX_END_NAMESPACE_VERSION
	} // namespace
	
	#endif