Question

我试图更多地了解STL容器；现在，我已经阅读并使用了std::back_insert_iterator，所以我想创建一个类似的类仅用于教育目的：

template <typename container>
class BackInsertIter {
    public:
        BackInsertIter() = delete;
        explicit BackInsertIter(container&);
        BackInsertIter& operator*();
        BackInsertIter& operator=( typename container::const_reference);

        container* container_;
};

template <typename container>
BackInsertIter<container>::BackInsertIter(container& cont) : 
    container_(&cont){

}

template <typename container>
BackInsertIter<container>& BackInsertIter<container>::operator*() {
    return *this;
}

template <typename container>
BackInsertIter<container>& BackInsertIter<container>::operator=(typename container::const_reference val) {
    container_->.push_back(val);
    return *this;
}

template <typename container>
BackInsertIter<container> Back_Insert(container& cont) {
    return BackInsertIter<container>(cont);
}


int main() {

    std::vector<int> vi;
    BackInsertIter< std::vector<int>> bivi(vi);

    *bivi = 57;
    *bivi = 10;
    *bivi = 24;
    *bivi = 81;


    for (auto i : vi)
        std::cout << i << ", ";
    std::cout << std::endl;

    std::list<std::string> lstr;
    BackInsertIter<std::list<std::string>> bilstr(lstr);

    *bilstr = "Hello to";
    *bilstr = "C++";
    *bilstr = "World!";

    for (const auto& str : lstr)
        std::cout << str << " ";
    std::cout << std::endl;

    vi.clear();

    auto it1 = Back_Insert(vi);
    *it1 = 1;
    *it1 = 2;
    *it1 = 3;
    *it1 = 4;
    *it1 = 5;

    for (auto i : vi)
        std::cout << i << ", ";
    std::cout << std::endl;

    auto it2 = Back_Insert(lstr);
    *it2 = "Ahmed";
    *it2 = "Programmer";

    for (const auto& str : lstr)
        std::cout << str << " ";
    std::cout << std::endl;

    vi.clear();

    std::cout << "enter integer values for vector folloed by endline character (ctrl+z): " << std::endl;
    std::copy(std::istream_iterator<int>(std::cin), std::istream_iterator<int>(),
        Back_Insert(vi));

    for (const auto& i : vi)
        std::cout << i << " ";
    std::cout << std::endl;

}

在我尝试将我的Back_Insert_Iterator传递到std::copy并出现此错误的地方，代码才能正常工作：

“严重性代码描述项目文件行错误C4996'std :: _ Copy_impl'：使用参数可能不安全的函数调用-此调用依赖于调用者检查传递的值是否正确。要禁用此警告，请使用-D_SCL_SECURE_NO_WARNINGS。请参阅有关如何使用Visual C ++'Checked Iterators'ConsoleApplication1 c：\ program files（x86）\ Microsoft Visual Studio 14.0 \ vc \ include \ xutility 2230的文档 “

为什么我不能将Back_Insert_Iterator传递给std :: copy？

0 个答案: