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inheriting vectors and initialization

开发者 https://www.devze.com 2023-02-01 08:22 出处:网络
Am trying to inherit a class from a C++ vector and initialize it at the constructor. How do I do it? For example:

Am trying to inherit a class from a C++ vector and initialize it at the constructor. How do I do it? For example:

class Dataset:public std::vector<float>{
    public:
            Dataset(vector<float> val):*baseclass*(va开发者_高级运维l){}
            // bruteforce way. // Dataset(vector<float> val){//for every val[i] call push_back(val[i]);}

ofcourse there's nothing as baseclass, what I mean by the above statement is I want to initialize the vector's data with val. how do I do it without push_back ing every element?


Don't derive from std::vector<>. This class was never meant to be derived from. Use an instance of the class as a member instead:

struct Owns {
    Owns() : the_vector_(42, 128) { }

private:
    std::vector<float> the_vector_;
};


You could write :

Dataset(const vector<float> &val): std::vector<float>(val) {}

but in the end, you really shouldn't inherit publicly from std::vector. There are multiple hints which show that std::vector is just not meant to be derived :

  • No virtual destructor
  • No protected members
  • No virtual functions

You can't prevent anyone from treating your Dataset object as a std::vector<float>, because public inheritance means that Dataset is a std::vector<float>, and this will fail miserably if someone attempts to delete a Database object through a std::vector<float> pointer.

If you want to reuse std::vector, either use a private std::vector member, or inherit privately and expose what should be through using declarations.

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