Explicit base class ctor call or not

{ Short answer: you don't have to explicitly mention the base ctor,
  and even so the base ctor is required to be called: you cannot skip
  calling the base ctor. -mod/sk }

When defining a ctor in a derived class, either with parameters or
not, do I have to explicitly call the base ctor or is it automatic?

Given simple code like:

class Base {
public:
Base() {cout << "Base ctor" << endl;}
};

class Derived : public Base {
public:
Derived() {cout << "Derived ctor" << endl;}
};

int main() {
Derived* d = new Derived();
}

do I have to explicitly call Base ctor from Derived ctor if I want to
adhere C++ standard. Seems that g++ does this automatically so writing

Derived() : Base() {cout << "Derived ctor" << endl;}

is not needed in order to have a call to Base ctor.

Any reference to C++ standard would be appreciated. Looking at
Stroustrup's book didn't solve the "mystery".

Thanks,
--
Wellu

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