Monostate idiom example in C++

CMakeLists.txt

cmake_minimum_required(VERSION 3.16)
project(monostate_idiom)

set(CMAKE_CXX_STANDARD 17)
add_library(monostate monostate.cpp)

add_executable(monostate_idiom main.cpp)
target_link_libraries(monostate_idiom monostate)

main.cpp

#include <iostream>
#include "monostate.h"

int main() {
    Monostate monostate{};

    std::cout << "and the answer is... " << monostate.GetTheAnswer() << std::endl;
    return 0;
}

monostate.cpp

//
// Created by angelos on 05/06/2020.
//
#include "monostate.h"
static int answer = 42;

int Monostate::GetTheAnswer() const {
    return answer;
}

monostate.h

//
// Created by angelos on 05/06/2020.
//

#ifndef MONOSTATE_IDIOM_MONOSTATE_H
#define MONOSTATE_IDIOM_MONOSTATE_H
class Monostate {
public:
    int GetTheAnswer() const;
};
#endif//MONOSTATE_IDIOM_MONOSTATE_H