I am trying to write a simple program in C++ and I get a linker error that has been driving me crazy for the past 3 days. I have managed to get it down to a minimal (non) working example.
So I have in the same folder 3 files: main.cpp, ComGameTypes.h and ComGameTypes.cpp.
The contents are:
main.cpp:
#include <iostream>
#include "ComGameTypes.h"
int main()
{
GameState gs;
gs.get(1);
return 0;
};
ComGameTypes.h:
#pragma once
#include <iostream>
#include <array>
class GameState
{
public:
std::array<int, 27> data;
int get(int);
GameState();
};
ComGameTypes.cpp:
#include "ComGameTypes.h"
inline int GameState::get(int i)
{
return data[i];
};
GameState::GameState()
{
std::cout << "Gamestate constructor running\n";
for (int i = 0; i < 27; i++)
{
data[i] = 0;
}
};
When I try to compile by g++ .\main.cpp .\ComGameTypes.cpp -o a this I get a linker error that there is an undefined reference to 'GameState::get(int)'.
The kicker is that if I add the line #include "ComGameTypes.cpp" in main.cpp and run g++ .\main.cpp -o a it compiles without errors! What causes this?
