Who calls constructor in virtual inheritance? [duplicate]

This question already has answers here: c++ virtual inheritance (3 answers) Closed 9 years ago.

#include<iostream>

class base{
public:
base(){std::cout<<"In base";}
};

class dv1:virtual private base {
public:
dv1(){std::cout<<"In DV1";}
};

class dv2:virtual private base {
public:
dv2(){std::cout<<"In 开发者_JAVA百科DV2";}
};

class drv : public dv1, public dv2 {
public:
drv() {std::cout<<"Why is this working";}
};

int main() {
drv obj;

return 0;
}

Isn't in case of virtual inheritance, it is the responsibility of most derive class to call the constructor? Note: Here base is inherited virtually and privately.

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Your constructor of drv didn't explicitly call the constructors of its base class(es), so the compiler will generate a call to the parameterless constructor of the base class