Question

I would like to build two C++ projects in the same solution in Visual Studio 2010 that can interact with each other. I have created a solution under directory C:\Users\me\Desktop\SolutionDir. The two projects have been created respectively under C:\Users\me\Desktop\SolutionDir\FirstProject and C:\Users\me\Desktop\SolutionDir\SecondProject.

My first project contains two files, a header function.h and a cpp file function.cpp

function.h

#pragma once
void print_stuff();

function.cpp

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

void print_stuff() {
    std::cout << "hello world" << std::endl;
}  

My second project contains the main file main.cpp

main.cpp

#include "FirstProject\function.h"
#include <iostream>

int main(void) {
    print_stuff();

    int stop;
    std::cin >> stop;
    return 0;
}  

I added the directory C:\Users\me\Desktop\SolutionDir\ in my SecondProject Configuration Properties > C/C++ > General > Additional Include Directories. I still get the classical error : error LNK2019: unresolved external symbol when calling the function print_stuff().

Any ideas ?

Answer 1

Try building the first project as a Static Library in Project Properties/Configuration Properties/General/Configuration Type.

Then in your project properties for the second project, you’ll need to change two things:

1. In Linker/General, you might need to add to “Additional Library Directories” the folder where the first project’s .lib is built.
2. In Linker/Input, you will need to add to Additional Dependencies the name of the .lib file like FirstProject.lib or whatever its name is.