final Specifier

 

The latest version of this topic can be found at final Specifier.

You can use the final keyword to designate virtual functions that cannot be overridden in a derived class. You can also use it to designate classes that cannot be inherited.

Syntax

  
function-declaration final;  
  
class class-name final base-classes  

Remarks

final is context-sensitive and has special meaning only when it's used after a function declaration or class name; otherwise, it's not a reserved keyword.

When final is used in class declarations, base-classes is an optional part of the declaration.

Example

The following example uses the final keyword to specify that a virtual function cannot be overridden.

class BaseClass  
{  
    virtual void func() final;  
};  
  
class DerivedClass: public BaseClass  
{  
    virtual void func(); // compiler error: attempting to   
                         // override a final function  
};  

For information about how to specify that member functions can be overridden, see override Specifier.

The next example uses the final keyword to specify that a class cannot be inherited.

class BaseClass final   
{  
};  
  
class DerivedClass: public BaseClass // compiler error: BaseClass is   
                                     // marked as non-inheritable  
{  
};  

See Also

Keywords
(NOTINBUILD) C++ Type Names
override Specifier