C++ – LNK2019: unresolved external symbol in VS unit-testing

clinker-errorslnk2019unit testingvisual studio

I get the error as stated in the title. I ensured the following:
– The Include directory, include library and additional include directory are set correctly
– In the properties, Subsystem is set to CONSOLE

Comments to my code:
LifeLib is a project that contains classes of that I want to test some methods. The classes are defined in namespace LifeLib. One of them is StornoTafel. testVariables is NOT defined in any namespace.
I get the linking error 3 times, for 2 constructors and 1 method in StornoTafel (noted in the code).

//project Tester
#include "stdafx.h"
#include "CppUnitTest.h"

#include "../LifeLib/StornoTafel.h"
#include "../LifeLib/testVariables.h"

using namespace Microsoft::VisualStudio::CppUnitTestFramework;

namespace Tester
{       
    TEST_CLASS(AggSelTest)
    {
    public:
        LifeLib::StornoTafel stornoTafel_; // LNK2019
        LifeLib::StornoTafel *stornoTafel_; // no error, but I need an instance and not a reference to proceed -> see init method
        LifeLib::testVariables test_vars_; // everything is fine

        TEST_METHOD_INITIALIZE(init) {
            stornoTafel_ = StornoTafel(test_vars_.lapseProb); // when this line is commented out I only get the first error (see below)
        }
    }
}

// testVariables.h
#pragma once
#include <iostream>
#include <vector>

class testVariables {
public:
    testVariables() {};
// here are a lot of vectors with values for testing purposes
std::vector<double> _lapseProb= {0,1,2}; // [...]
};

// StornoTafel.h
#pragma once
#include "masterheader.h"

namespace LifeLib {
    class StornoTafel {
    public:

        StornoTafel(); //LNK2019
        StornoTafel(std::vector<double> ProbabilityOfLapseInYearT); //LNK2019

        StornoTafel(const StornoTafel &obj); //no error

        StornoTafel operator=(StornoTafel const& rhs); //LNK2019

        //! \name Getter
        //@{ 
        const std::vector<double>& Stornowahrscheinlichkeit() const;
        //@}
    protected:
        std::vector<double> Stornowahrscheinlichkeit_;
    };
    inline const std::vector<double>& StornoTafel::Stornowahrscheinlichkeit() const {
        return Stornowahrscheinlichkeit_;
    }
}

//StornoTafel.cpp
#include "StornoTafel.h"

LifeLib::StornoTafel::StornoTafel() {
}

LifeLib::StornoTafel::StornoTafel(std::vector<double> ProbabilityOfLapseInYearT) {
    Stornowahrscheinlichkeit_ = ProbabilityOfLapseInYearT;
}

LifeLib::StornoTafel::StornoTafel(const StornoTafel &obj) {
    Stornowahrscheinlichkeit_ = obj.Stornowahrscheinlichkeit_;
}

LifeLib::StornoTafel LifeLib::StornoTafel::operator=(StornoTafel const& rhs) {
    Stornowahrscheinlichkeit_ = rhs.Stornowahrscheinlichkeit_;
    return *this;
}

//masterheader.h
#pragma once
#include <fstream>
#include <iostream>
#include <sstream>
#include <string>

#include <algorithm>
#include <ctime>

errors in detail:

  1. LNK2019 unresolved external symbol "public: __cdecl
    LifeLib::StornoTafel::StornoTafel(void)"
    (??0StornoTafel@LifeLib@@QEAA@XZ) referenced in function "public:
    __cdecl AggSelTester::AggSelTest::AggSelTest(void)" (??0AggSelTest@AggSelTester@@QEAA@XZ)
  2. LNK2019 unresolved external
    symbol "public: __cdecl LifeLib::StornoTafel::StornoTafel(class
    std::vector >)"
    (??0StornoTafel@LifeLib@@QEAA@V?$vector@NV?$allocator@N@std@@@std@@@Z)
    referenced in function "public: void __cdecl
    AggSelTester::AggSelTest::init(void)"
    (?init@AggSelTest@AggSelTester@@QEAAXXZ)
  3. LNK2019 unresolved external
    symbol "public: class LifeLib::StornoTafel __cdecl
    LifeLib::StornoTafel::operator=(class LifeLib::StornoTafel const &)"
    (??4StornoTafel@LifeLib@@QEAA?AV01@AEBV01@@Z) referenced in function
    "public: void __cdecl AggSelTester::AggSelTest::init(void)"
    (?init@AggSelTest@AggSelTester@@QEAAXXZ)

Why do they arise?

Best Answer

I found the answer by myself: I have to include the .cpp file.
So #include "../LifeLib/StornoTafel.cpp" fixes the error. However, I have no idea why.

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