c++ - Abstract base member variable in base class -

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i want specify interface requires abstract class have type member variable.

i'll try replicate situation here:

class blob {   int data[32]; }; class worker {   string name;   abstract void workon(blob&) = 0; }  class abstract {   vector<shared_ptr<w>> workerlist;   blob allthestuff;   abstract void somethingelse() = 0;   void doallthework() {     (w : workerlist) {       w->workon(allthestuff);     }   } };  class b_blob : public blob {   int moredata[4096]; };  class bulbasaurtrainingcamp : public abstract {   b_blob allthestuff;   void somethingelse() {} // implemented   // class accept bulbasaurs workerlist };  class bulbasaur : worker {   bulbasaur(): name("fushigidane") {}   void workon(blob& b) {     // bulbasaurs cover *all* workspace crap     (int i=0; i<sizeof(b.data[0])/sizeof(b.data); ++i) {       b.data[i] = *((int*)&("crap"));     }     (i=0; i<sizeof(b.moredata[0])/sizeof(b.moredata); ++i) {       b.moredata[i] = *((int*)&("crap"));     } }

here, abstract bas class has blob, instance of bulbasaurtrainingcamp has derived b_blob. appears since gave same name, compiler accepts it.

is there name this? want know behavior when this. have overridden blob b_blob?

i not sure whether there inaccessible base blob instance hanging around inside of bulbasaurtrainingcamp. expectation each bulbasaur write 16512 (not 16384) bytes of crap across 2 member variables of b_blob. hoping c++ appears sensible thing. it's case of, "it compiles think should happy, i'm still not totally sure it's doing think should doing".

#include<iostream> #include<vector> using namespace std;  int main() {     class base     {     public:          int samename;         base(int x):samename(x){}     };     class derived : public base     {     public:         int diffname;         int samename;         derived(int x,int i,int j):base(x),diffname(i),samename(j){}      };     derived example(1,2,3);     cout<<example.samename<<endl;     cout<<example.diffname<<endl;     cout<<example.base::samename<<endl; }

the result 3 2 1. hope example helpful.


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