C++ redefinition of function - c++

Question

I have a base class and 3 separate derived classes. All of the .hpp files are structured the same.
The .hpp which doesn't work:
#ifndef CAESARCIPHER_HPP
#define CAESARCIPHER_HPP
#include "Cipher.hpp"
#include<string>
class CaesarCipher : public Cipher {
public:
CaesarCipher(Key key)
: Cipher{ key } {}
std::string getCipherTypeString() const override {}
};
#endif
The .cpp of it (haven't implemented anything yet):
#include "CaesarCipher.hpp"
#include "Cipher.hpp"
#include<iostream>
CaesarCipher::CaesarCipher(Key key)
: Cipher{ key } {}
std::string CaesarCipher::getCipherTypeString() const {
return "";
}
One .hpp that does work:
#ifndef ASCIICIPHER_HPP
#define ASCIICIPHER_HPP
#include "Cipher.hpp"
#include<string>
class AsciiCipher : public Cipher {
public:
AsciiCipher(Key key)
: Cipher{ key } {}
std::string getCipherTypeString() const override {}
};
#endif
The base.hpp class looks like this:
typedef uint64_t Key;
#ifndef BASE_HPP
#define BASE_HPP
#include <string>
class Cipher {
Key key_;
public:
Cipher(Key key){}
virtual std::string getCipherTypeString() const {}
};
#endif
Errors:
CaesarCipher.cpp:6:15: error: redefinition of 'CaesarCipher'
CaesarCipher::CaesarCipher(Key key)
^
./CaesarCipher.hpp:9:9: note: previous definition is here
CaesarCipher(Key key)
^
CaesarCipher.cpp:9:27: error: redefinition of 'getCipherTypeString'
std::string CaesarCipher::getCipherTypeString() const {
^
./CaesarCipher.hpp:12:21: note: previous definition is here
std::string getCipherTypeString() const override {}
^
The problem is that 2 of the derived classes work perfectly but for one I get the above mentioned error for all of the functions. They look all the same just with changed names etc.

Answer 1

You have to:
Define the type Key.
Provide the missing body for the definition of Base::Base(Key).
Add a return statement to all functions that return non-void.
That should fix the errors that you are getting.