Derived class not inheriting overloaded method fro

问题:

I would like to have a method in a base class call a pure virtual method that will be implemented in a derived class. However, the base class parameterless method doesn't seem to be inherited by the derived class. What am I doing wrong? Compiler is MSVC12.

error C2660: 'Derived::load' : function does not take 0 arguments

Here is a complete example (that doesn't compile due to the error):

struct Base
{
    void load() { load(42); }; // Making this virtual doesn't matter.
    virtual void load(int i) = 0;
};

struct Derived : Base
{
    virtual void load(int i) {};
};

int main()
{
    Derived d;
    d.load(); // error C2660: 'Derived::load' : function does not take 0 arguments
}

回答1:

Oh, the derived class does inherit void load().

But you are declaring void load(int i) in the derived class, which means it is shadowed.

Add using Base::load; to Derived to add all non-overridden definitions of load from Base to the overload-set in Derived.

Alternatively, call the Base-class-version explicitly with the scope-resolution-operator d.Base::load();.

回答2:

You have to call the Base one explicitly: d.Base::load();. I have no idea why, but it works. My guess is that overriding hides all overloads.