Copy constructor is not inherited

I've got the following code:

class C {
public:
    C(int) {}
    C(const C&) {}
    C() {}
};  

class D : public C { 
public:
    using C::C;
};  

int main() {
    C c;
    D d_from_c(c); // does not compile, copy ctor is not inherited
    D d_from_int(1); // compiles, C(int) is inherited
}   

Derived class should inherit all ctors of base except the default ctor (it is explained here). But why copy ctor is not inherited as well? Arguments from the related question are not acceptable here.

The code is compiled with g++ 4.8.1.

Because the standard says so. [class.inhctor]/p3, emphasis mine:

For each non-template constructor in the candidate set of inherited constructors other than a constructor having no parameters or a copy/move constructor having a single parameter, a constructor is implicitly declared with the same constructor characteristics unless there is a user-declared constructor with the same signature in the complete class where the using-declaration appears or the constructor would be a default, copy, or move constructor for that class.