// Debugging array implementation -*- C++ -*-

// Copyright (C) 2012-2013 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 debug/array
 *  This is a Standard C++ Library header.
 */

#ifndef _GLIBCXX_DEBUG_ARRAY
#define _GLIBCXX_DEBUG_ARRAY 1

#pragma GCC system_header

#include <debug/safe_sequence.h>

namespace std _GLIBCXX_VISIBILITY(default)
{
namespace __debug
{
  template<typename _Tp, std::size_t _Nm>
    struct array
    {
      typedef _Tp 	    			      value_type;
      typedef value_type*			      pointer;
      typedef const value_type*                       const_pointer;
      typedef value_type&                   	      reference;
      typedef const value_type&             	      const_reference;
      typedef value_type*                             iterator;
      typedef const value_type*                       const_iterator;
      typedef std::size_t                    	      size_type;
      typedef std::ptrdiff_t                   	      difference_type;
      typedef std::reverse_iterator<iterator>	      reverse_iterator;
      typedef std::reverse_iterator<const_iterator>   const_reverse_iterator;

      // Support for zero-sized arrays mandatory.
      typedef _GLIBCXX_STD_C::__array_traits<_Tp, _Nm> _AT_Type;
      typename _AT_Type::_Type                         _M_elems;

      template<std::size_t _Size>
	struct _Array_check_subscript
 	{
	  std::size_t size() { return _Size; }

	  _Array_check_subscript(std::size_t __index)
	  { __glibcxx_check_subscript(__index); }
        };

      template<std::size_t _Size>
	struct _Array_check_nonempty
 	{
	  bool empty() { return _Size == 0; }

	  _Array_check_nonempty()
	  { __glibcxx_check_nonempty(); }
        };

      // No explicit construct/copy/destroy for aggregate type.

      // DR 776.
      void
      fill(const value_type& __u)
      { std::fill_n(begin(), size(), __u); }

      void
      swap(array& __other)
      noexcept(noexcept(swap(std::declval<_Tp&>(), std::declval<_Tp&>())))
      { std::swap_ranges(begin(), end(), __other.begin()); }

      // Iterators.
      iterator
      begin() noexcept
      { return iterator(data()); }

      const_iterator
      begin() const noexcept
      { return const_iterator(data()); }

      iterator
      end() noexcept
      { return iterator(data() + _Nm); }

      const_iterator
      end() const noexcept
      { return const_iterator(data() + _Nm); }

      reverse_iterator 
      rbegin() noexcept
      { return reverse_iterator(end()); }

      const_reverse_iterator 
      rbegin() const noexcept
      { return const_reverse_iterator(end()); }

      reverse_iterator 
      rend() noexcept
      { return reverse_iterator(begin()); }

      const_reverse_iterator 
      rend() const noexcept
      { return const_reverse_iterator(begin()); }

      const_iterator
      cbegin() const noexcept
      { return const_iterator(data()); }

      const_iterator
      cend() const noexcept
      { return const_iterator(data() + _Nm); }

      const_reverse_iterator 
      crbegin() const noexcept
      { return const_reverse_iterator(end()); }

      const_reverse_iterator 
      crend() const noexcept
      { return const_reverse_iterator(begin()); }

      // Capacity.
      constexpr size_type 
      size() const noexcept { return _Nm; }

      constexpr size_type 
      max_size() const noexcept { return _Nm; }

      constexpr bool 
      empty() const noexcept { return size() == 0; }

      // Element access.
      reference
      operator[](size_type __n)
      {
	__glibcxx_check_subscript(__n);
	return _AT_Type::_S_ref(_M_elems, __n);
      }

      constexpr const_reference
      operator[](size_type __n) const noexcept
      {
	return __n < _Nm ? _AT_Type::_S_ref(_M_elems, __n)
	 : (_GLIBCXX_THROW_OR_ABORT(_Array_check_subscript<_Nm>(__n)),
	    _AT_Type::_S_ref(_M_elems, 0));
      }

      reference
      at(size_type __n)
      {
	if (__n >= _Nm)
	  std::__throw_out_of_range(__N("array::at"));
	return _AT_Type::_S_ref(_M_elems, __n);
      }

      constexpr const_reference
      at(size_type __n) const
      {
	// Result of conditional expression must be an lvalue so use
	// boolean ? lvalue : (throw-expr, lvalue)
	return __n < _Nm ? _AT_Type::_S_ref(_M_elems, __n)
	  : (std::__throw_out_of_range(__N("array::at")),
	     _AT_Type::_S_ref(_M_elems, 0));
      }

      reference 
      front()
      {
	__glibcxx_check_nonempty();
	return *begin();
      }

      constexpr const_reference 
      front() const
      {
	return _Nm ? _AT_Type::_S_ref(_M_elems, 0)
	  : (_GLIBCXX_THROW_OR_ABORT(_Array_check_nonempty<_Nm>()),
	     _AT_Type::_S_ref(_M_elems, 0));
      }

      reference 
      back()
      {
	__glibcxx_check_nonempty();
	return _Nm ? *(end() - 1) : *end();
      }

      constexpr const_reference 
      back() const
      {
	return _Nm ? _AT_Type::_S_ref(_M_elems, _Nm - 1)
	  : (_GLIBCXX_THROW_OR_ABORT(_Array_check_nonempty<_Nm>()),
	     _AT_Type::_S_ref(_M_elems, 0));
      }

      pointer
      data() noexcept
      { return std::__addressof(_AT_Type::_S_ref(_M_elems, 0)); }

      const_pointer
      data() const noexcept
      { return std::__addressof(_AT_Type::_S_ref(_M_elems, 0)); }
    };

  // Array comparisons.
  template<typename _Tp, std::size_t _Nm>
    inline bool 
    operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
    { return std::equal(__one.begin(), __one.end(), __two.begin()); }

  template<typename _Tp, std::size_t _Nm>
    inline bool
    operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
    { return !(__one == __two); }

  template<typename _Tp, std::size_t _Nm>
    inline bool
    operator<(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b)
    { 
      return std::lexicographical_compare(__a.begin(), __a.end(),
					  __b.begin(), __b.end()); 
    }

  template<typename _Tp, std::size_t _Nm>
    inline bool
    operator>(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
    { return __two < __one; }

  template<typename _Tp, std::size_t _Nm>
    inline bool
    operator<=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
    { return !(__one > __two); }

  template<typename _Tp, std::size_t _Nm>
    inline bool
    operator>=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
    { return !(__one < __two); }

  // Specialized algorithms.
  template<typename _Tp, std::size_t _Nm>
    inline void
    swap(array<_Tp, _Nm>& __one, array<_Tp, _Nm>& __two)
    noexcept(noexcept(__one.swap(__two)))
    { __one.swap(__two); }

  template<std::size_t _Int, typename _Tp, std::size_t _Nm>
    constexpr _Tp&
    get(array<_Tp, _Nm>& __arr) noexcept
    {
      static_assert(_Int < _Nm, "index is out of bounds");
      return _GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::
	_S_ref(__arr._M_elems, _Int);
    }

  template<std::size_t _Int, typename _Tp, std::size_t _Nm>
    constexpr _Tp&&
    get(array<_Tp, _Nm>&& __arr) noexcept
    {
      static_assert(_Int < _Nm, "index is out of bounds");
      return std::move(get<_Int>(__arr));
    }

  template<std::size_t _Int, typename _Tp, std::size_t _Nm>
    constexpr const _Tp&
    get(const array<_Tp, _Nm>& __arr) noexcept
    {
      static_assert(_Int < _Nm, "index is out of bounds");
      return _GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::
	_S_ref(__arr._M_elems, _Int);
    }
} // namespace __debug

  // Tuple interface to class template array.

  /// tuple_size
  template<typename _Tp, std::size_t _Nm>
    struct tuple_size<__debug::array<_Tp, _Nm>>
    : public integral_constant<std::size_t, _Nm> { };

  /// tuple_element
  template<std::size_t _Int, typename _Tp, std::size_t _Nm>
    struct tuple_element<_Int, __debug::array<_Tp, _Nm>>
    {
      static_assert(_Int < _Nm, "index is out of bounds");
      typedef _Tp type;
    };
} // namespace std

#endif // _GLIBCXX_DEBUG_ARRAY