redefinition of 'class name'

[nettlock]

Hello

my problem is :

I have an interface

class IAnexable 
{
    public:
        virtual IAnexable* anexar( char c ) const=0 ;
        virtual IAnexable* anexar( SecuenciaCaracter* sc ) const=0;
        virtual IAnexable* anexar( SecuenciaCaracter* sc, int inicio, int fin ) const=0;
};

from which it inherits the following abstract class

class AbstractConstructorCadena :  public SecuenciaCaracter,public IAnexable
    {
        public:
                AbstractConstructorCadena();
                AbstractConstructorCadena(const AbstractConstructorCadena& orig);
                //IMPLEMENTACION ANEXABLE
                virtual AbstractConstructorCadena* anexar( char c )  {}
                virtual AbstractConstructorCadena* anexar(SecuenciaCaracter* sc ){}
                virtual AbstractConstructorCadena* anexar( SecuenciaCaracter*sc, int inicio, int fin ) {}
                
                int longitud();
                char obtenerCaracter( char caracter );
                SecuenciaCaracter* subSecuencia( int inicio, int fin );
                String* aString();
                virtual ~AbstractConstructorCadena();
        private:

   };

that does not implement any method.
And the class that will implement the methods are as follows

class StringBuffer :  public AbstractConstructorCadena
    {
        public:
            StringBuffer();
            StringBuffer(const StringBuffer& orig);
            
            StringBuffer* anexar( char c );
            StringBuffer* anexar( SecuenciaCaracter* sc );
            StringBuffer* anexar(SecuenciaCaracter* sc, int inicio, int fin );
          
            virtual ~StringBuffer();
        private:

    };

the problem is that I have the string buffer class that inherits from an abstract class does not implement AbstracConstructorCadena and methods tells me that no reference to the constructor of AbstracConstructorCadena, but then the solution is to declare them inline, but do not want to deploy the code in the StringBuffer class header but in the. cpp, and clearly to make the statement inline in the header, and perform the implementation in the. cpp fails me Some solution

sorry for my bad English

thanks