# C++ Name hiding

**[Name hiding](https://en.cppreference.com/w/cpp/language/lookup)** occurs when a derived class member function has the same name as a base class member function but different parameters. The derived function hides all base functions with that name, even overloads, making them inaccessible through the derived object unless explicitly qualified.

Use `using` to bring base class overloads into the derived scope, or use virtual functions for polymorphic behavior.

## Example

This example shows name hiding making base overloads inaccessible and how using fixes it.

```cpp
// compile: g++ -o hiding hiding.cpp
// run: ./hiding
// description: name hiding in derived classes and how 'using' fixes it

#include <iostream>

class Base {
public:
    void func(int x) { std::cout << "Base::func(int)\n"; }
};

class DerivedBad : public Base {
public:
    void func(double x) { std::cout << "DerivedBad::func(double)\n"; }
    // Base::func(int) is hidden
};

class DerivedGood : public Base {
public:
    using Base::func;  // bring base overloads into scope
    void func(double x) { std::cout << "DerivedGood::func(double)\n"; }
};

int main() {
    DerivedBad db;
    // db.func(42);  // error: hidden by derived func(double)
    
    DerivedGood dg;
    dg.func(42);    // OK: Base::func(int) visible
    dg.func(3.14);  // OK: DerivedGood::func(double)
    
    return 0;
}
```