找不到解除引用的指针。 C ++

Question

我创建了一个复制ctor和复制操作符。在他们之间和'擦除（迭代器我）'我设法取消引用指针但我找不到。

square_list erase（iterator i）

template<class list>
void square_list<list>::erase( iterator i )
{
if( i == end() )
    return;
linked_list_iterator<list> delIter( i.getNode() );
i++;
i.getHead()->data.erase( delIter );
--_size;
squarify();

}

复制ctor

square_list( square_list & slCopy) {
    _size = 0;
    for( auto it = slCopy.cbegin(); it != slCopy.cend(); ++it)
    {
        insert(*it);
    }
}

复制操作员

square_list& operator = ( square_list & rhs) {
    clear();
    for (auto it = rhs.begin(); it != rhs.end(); ++it) {
        insert( *it);
    }

    return *this;
}

linked_list erase（iterator_t i）

template <class list>
void linked_list<list>::erase(iterator_t i)
{
node_ptr_t tmpNode = i.getNode();
if(i.getNode() == _head) {
    _head = i.getNode()->next;
}
if(i.getNode() == _tail) {
    _tail = i.getNode()->prev;
}

if( i.getNode()->next )
    i = iterator_t( i.getNode()->next );
else if( i.getNode()->prev)
    i = iterator_t( i.getNode()->prev );

if(tmpNode->prev)
    tmpNode->prev->next = tmpNode->next;
else
    tmpNode->prev = nullptr;
if(tmpNode->next)
    tmpNode->next->prev = tmpNode->prev;
else
    tmpNode->prev = nullptr;

delete tmpNode;
--_size;
}