/*

 * Copyright (c) 2003

 * Francois Dumont

 *

 * This material is provided "as is", with absolutely no warranty expressed

 * or implied. Any use is at your own risk.

 *

 * Permission to use or copy this software for any purpose is hereby granted

 * without fee, provided the above notices are retained on all copies.

 * Permission to modify the code and to distribute modified code is granted,

 * provided the above notices are retained, and a notice that the code was

 * modified is included with the above copyright notice.

 *

 */

/*

 * All the necessary methods used for template expressions with basic_string

 * This file do not have to be macro guarded as it is only used in the _string.h

 * file and it is a part of the basic_string definition.

 */

public:

  template <class _Left, class _Right, class _StorageDir>

  basic_string(_STLP_PRIV __bstr_sum<_CharT, _Traits, _Alloc, _Left, _Right, _StorageDir> const& __s)

    : _STLP_STRING_SUM_BASE(_Reserve_t(), __s.size(), __s.get_allocator())

  { _M_append_sum(__s); }

  template <class _Left, class _Right, class _StorageDir>

  basic_string(_STLP_PRIV __bstr_sum<_CharT, _Traits, _Alloc, _Left, _Right, _StorageDir> const& __s,

               size_type __pos, size_type __n = npos,

               const allocator_type& __a = allocator_type())

    : _STLP_STRING_SUM_BASE(_Reserve_t(), (__pos <= __s.size()) ? ((min) (__n, __s.size() - __pos)) : 0, __a) {

    size_type __size = __s.size();

    if (__pos > __size)

      this->_M_throw_out_of_range();

    else

      _M_append_sum_pos(__s, __pos, (min) (__n, __size - __pos));

  }

private:

  _CharT* _M_append_fast(_STLP_PRIV __char_wrapper<_CharT> __c, _CharT *__buf) {

    _STLP_STD::_Copy_Construct(__buf, __c.getValue());

    return __buf + 1;

  }

  _CharT* _M_append_fast(_CharT const* __s, size_type __s_size, _CharT *__buf)

  { return uninitialized_copy(__s, __s + __s_size, __buf); }

  _CharT* _M_append_fast(_STLP_PRIV __cstr_wrapper<_CharT> const& __s, _CharT *__buf)

  { return _M_append_fast(__s.c_str(), __s.size(), __buf); }

  _CharT* _M_append_fast(_STLP_PRIV __bstr_wrapper<_CharT, _Traits, _Alloc> __s, _CharT *__buf)

  { return _M_append_fast(__s.b_str(), __buf); }

  _CharT* _M_append_fast(_Self const& __s, _CharT *__buf)

  { return _M_append_fast(__s.data(), __s.size(), __buf); }

  _CharT* _M_append_fast(_STLP_PRIV __sum_storage_elem<_CharT, _Traits, _Alloc> const&, _CharT *__buf)

  { return __buf; }

  template <class _Left, class _Right, class _StorageDir>

  _CharT* _M_append_fast(_STLP_PRIV __bstr_sum<_CharT, _Traits, _Alloc, _Left, _Right, _StorageDir> const& __s, _CharT *__buf)

  { return _M_append_fast(__s.getRhs(), _M_append_fast(__s.getLhs(), __buf)); }

  _CharT* _M_append_fast_pos(_STLP_PRIV __char_wrapper<_CharT> __c, _CharT *__buf, size_type /*__pos*/, size_type __n) {

    if (__n == 0)

      return __buf;

    _STLP_STD::_Copy_Construct(__buf, __c.getValue());

    return __buf + 1;

  }

  _CharT* _M_append_fast_pos(_CharT const* __s, size_type __s_size, _CharT *__buf,

                             size_type __pos, size_type __n)

  { return uninitialized_copy(__s + __pos, __s + __pos + (min)(__n, __s_size - __pos), __buf); }

  _CharT* _M_append_fast_pos(_STLP_PRIV __cstr_wrapper<_CharT> const& __s, _CharT *__buf,

                             size_type __pos, size_type __n)

  { return _M_append_fast_pos(__s.c_str(), __s.size(), __buf, __pos, __n); }

  _CharT* _M_append_fast_pos(_STLP_PRIV __bstr_wrapper<_CharT, _Traits, _Alloc> __s, _CharT *__buf,

                             size_type __pos, size_type __n)

  { return _M_append_fast_pos(__s.b_str(), __buf, __pos, __n); }

  _CharT* _M_append_fast_pos(_Self const& __s, _CharT *__buf,

                             size_type __pos, size_type __n)

  { return _M_append_fast_pos(__s.data(), __s.size(), __buf, __pos, __n); }

  _CharT* _M_append_fast_pos(_STLP_PRIV __sum_storage_elem<_CharT, _Traits, _Alloc> const&, _CharT *__buf,

                             size_type, size_type)

  { return __buf; }

  template <class _Left, class _Right, class _StorageDir>

  _CharT* _M_append_fast_pos(_STLP_PRIV __bstr_sum<_CharT, _Traits, _Alloc, _Left, _Right, _StorageDir> const& __s,

                             _CharT *__buf, size_type __pos, size_type __n) {

    if (__n == 0) {

      return __buf;

    }

    size_type __lhs_size = __s.getLhs().size();

    if (__pos < __lhs_size) {

      if (__n < (__lhs_size - __pos)) {

        return _M_append_fast_pos(__s.getLhs(), __buf, __pos, __n);

      } else {

        return _M_append_fast_pos(__s.getRhs(), _M_append_fast_pos(__s.getLhs(), __buf, __pos, __n),

                                  0, __n - (__lhs_size - __pos));

      }

    } else {

      return _M_append_fast_pos(__s.getRhs(), __buf, __pos - __lhs_size, __n);

    }

  }

  /* Note: We always force use of dynamic buffer if the short string optim option is activated

   * to avoid complicated code if the basic_string was instanciated with a non POD type.

   * In such a case we should use assignment for objects in the static array something that we

   * do not do.

   */

  size_type _M_get_additional_size(size_type __new_size, const __false_type& /*_Char_Is_POD*/) const {

#if defined (_STLP_USE_SHORT_STRING_OPTIM)

    //To avoid problem with the string assumptions, never allocate a dynamic buffer smaller or equal

    //than the static one:

    if (__new_size < _Base::_DEFAULT_SIZE + 1)

      return (_Base::_DEFAULT_SIZE + 1) - __new_size;

#endif /* _STLP_USE_SHORT_STRING_OPTIM */

    return 0;

  }

  size_type _M_get_additional_size(size_type, const __true_type& /*_Char_Is_POD*/) const

  { return 0; }

  template <class _Left, class _Right, class _StorageDir>

  _Self& _M_append_sum (_STLP_PRIV __bstr_sum<_CharT, _Traits, _Alloc, _Left, _Right, _StorageDir> const& __s) {

    size_type __s_size = __s.size();

    if (__s_size == 0)

      return *this;

    const size_type __old_size = this->size();

    if (__s_size > this->max_size() || __old_size > (this->max_size() - __s_size))

      this->_M_throw_length_error();

    size_type __offset_size = _M_get_additional_size(__old_size + __s_size, _Char_Is_POD());

    if (__old_size + __s_size + __offset_size > this->capacity()) {

      const size_type __len = __old_size + __offset_size + (max)(__old_size, __s_size) + 1;

      pointer __new_start = this->_M_end_of_storage.allocate(__len);

      pointer __new_finish = __new_start;

      _STLP_TRY {

        __new_finish = uninitialized_copy(this->_M_Start(), this->_M_Finish(), __new_start);

        __new_finish = this->_M_append_fast(__s, __new_finish);

        this->_M_construct_null(__new_finish);

      }

      _STLP_UNWIND((_STLP_STD::_Destroy_Range(__new_start,__new_finish),

                   this->_M_end_of_storage.deallocate(__new_start,__len)))

      this->_M_destroy_range();

      this->_M_deallocate_block();

      this->_M_reset(__new_start, __new_finish, __new_start + __len);

    }

    else {

      _M_append_sum_no_overflow(__s, 0, __s_size);

    }

    return *this;

  }

  template <class _Left, class _Right, class _StorageDir>

  _Self& _M_append_sum_pos(_STLP_PRIV __bstr_sum<_CharT, _Traits, _Alloc, _Left, _Right, _StorageDir> const& __s,

                           size_type __pos, size_type __n) {

    size_type __s_size = (min)(__s.size() - __pos, __n);

    if (__s_size == 0)

      return *this;

    const size_type __old_size = this->size();

    if (__s_size > this->max_size() || __old_size > (this->max_size() - __s_size))

      this->_M_throw_length_error();

    size_type __offset_size = _M_get_additional_size(__old_size + __s_size, _Char_Is_POD());

    if (__old_size + __s_size + __offset_size > this->capacity()) {

      const size_type __len = __old_size + __offset_size + (max)(__old_size, __s_size) + 1;

      pointer __new_start = this->_M_end_of_storage.allocate(__len);

      pointer __new_finish = __new_start;

      _STLP_TRY {

        __new_finish = uninitialized_copy(this->_M_Start(), this->_M_Finish(), __new_start);

        __new_finish = _M_append_fast_pos(__s, __new_finish, __pos, __s_size);

        this->_M_construct_null(__new_finish);

      }

      _STLP_UNWIND((_STLP_STD::_Destroy_Range(__new_start,__new_finish),

                   this->_M_end_of_storage.deallocate(__new_start,__len)))

      this->_M_destroy_range();

      this->_M_deallocate_block();

      this->_M_reset(__new_start, __new_finish, __new_start + __len);

    }

    else {

      _M_append_sum_no_overflow(__s, __pos, __s_size);

    }

    return *this;

  }

  template <class _Left, class _Right, class _StorageDir>

  void _M_append_sum_no_overflow(_STLP_PRIV __bstr_sum<_CharT, _Traits, _Alloc, _Left, _Right, _StorageDir> const& __s,

                                 size_type __pos, size_type __n) {

    pointer __finish = this->_M_Finish();

    _M_append_fast_pos(__s, __finish + 1, __pos + 1, __n - 1);

    _STLP_TRY {

      this->_M_construct_null(__finish + __n);

    }

    _STLP_UNWIND(this->_M_destroy_ptr_range(__finish + 1, __finish + __n))

    /* The call to the traits::assign method is only important for non POD types because the instance

     * pointed to by _M_finish has been constructed (default constructor) and should not be constructed

     * (copy constructor) once again. For POD it is irrelevant, uninitialized_copy could be fine,

     * but we are not going to make two implementations just for that.

     */

    _Traits::assign(*this->_M_finish, __s[__pos]);

    this->_M_finish += __n;

  }