C++ Header file “symbol(s) not found” error with classes

Question

Learning C++, I've looked around quite a bit and every time I seem to get a different answer that doesn't work, perhaps I'm just missing something.

I receive the following error:

"/Applications/CLion EAP.app/Contents/bin/cmake/bin/cmake" --build /Users/*/Library/Caches/clion10/cmake/generated/d7f7e267/d7f7e267/Debug --target hench_modules -- -j 8
Scanning dependencies of target hench_modules
[100%] Building CXX object CMakeFiles/hench_modules.dir/main.cpp.o
Linking CXX executable hench_modules
Undefined symbols for architecture x86_64:
"Console::log(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >)", referenced from:
_main in main.cpp.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[3]: *** [hench_modules] Error 1
make[2]: *** [CMakeFiles/hench_modules.dir/all] Error 2
make[1]: *** [CMakeFiles/hench_modules.dir/rule] Error 2
make: *** [hench_modules] Error 2

I'm using the JetBrains IDE "CLion"

Below is my code:

main.cpp:

//in main.cpp
#include "Console/console.h"

int main() {
    Console a; // no longer produces an error, because MyClass is defined
    a.log("Hello World!");
}

console.h:

#include <string>
class Console {
    public:
        void log(std::string str);
};

console.cpp:

#include "console.h"
#include <iostream>
using namespace std;

void Console::log(string str){
    cout << str << endl;
};

Any help is appreciated, the error only appears when actually calling a.log(); , prior to that there are no issues. As you can see the code is pretty simple and just following along a generic guide.

Answer 1

My issue seems to be with CMake, and very simple/silly.

Changes to the CMakeLists.txt file:

set(SOURCE_FILES
    Console/console.cpp
    Console/console.h
    main.cpp)

So the reason is as WhozCraig pointed out, the files were linked to and found by the code, but not actually built.