reserve.cpp

  template<typename _Tp, typename _Alloc>
    void
    vector<_Tp, _Alloc>::
    reserve(size_type __n)
    {
      if (__n > this->max_size())
        __throw_length_error(__N("vector::reserve"));
      if (this->capacity() < __n)
        {
          const size_type __old_size = size();
          pointer __tmp = _M_allocate_and_copy(__n,
            _GLIBCXX_MAKE_MOVE_IF_NOEXCEPT_ITERATOR(this->_M_impl._M_start),
            _GLIBCXX_MAKE_MOVE_IF_NOEXCEPT_ITERATOR(this->_M_impl._M_finish));
          std::_Destroy(this->_M_impl._M_start, this->_M_impl._M_finish,
                        _M_get_Tp_allocator());
          _M_deallocate(this->_M_impl._M_start,
                        this->_M_impl._M_end_of_storage
                        - this->_M_impl._M_start);
          this->_M_impl._M_start = __tmp;
          this->_M_impl._M_finish = __tmp + __old_size;
          this->_M_impl._M_end_of_storage = this->_M_impl._M_start + __n;
        }
    }