Question

I have been getting this error: ‘unresolved external symbol main referenced in function __tmainCRTStartup’ when I attempt to compile my c++ console application. I have done some searching and all I could find was changing my ‘linker’ from windows to console or vice versa. This didn’t work, I even tried creating a new console application.

I am unsure as to what is causing this, is it possible that template <typename T> is causing confusion as it appears in both files? Any help here would be much appreciated.

Code Below:

Main.cpp:

#include <iostream>
#include "tools.h"
using namespace tools;

template <typename T>
int main()
{
T input1;
T input2;

std::cout << "Enter in 1st number: " << endl;
std::cin >> input1;
std::cout << "Enter in 2nd number: " << endl;
std::cin >> input2;
std::cout << "num1 - num2 = [" << numberDifference(input1, input2) << "]" << endl;
getchar();
getchar();

return 0;
}

Tools.h:

#include <iostream>
namespace tools
{
template <typename T>
T numberDifference(T num1, T num2)
{
    if(num1 > num2)
        return num1 - num2;
    else
        return num2 - num1;
}
};

Answer 1

Remove the template definition for your main function.

Or at least call it from a proper main function.

e.g.

template< typename T >
int templated_main( int c, char** argv )
{
    // What was in your original main function....

}

int main( int c, char** argv )
{
    return templated_main<int>( c, argv );
}