Undefined reference to a class method [closed] - c++

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I have one class, Pose.hpp and Pose.cpp, and a main.cpp to use this, but when compile I'm getting error.
I'm using this to compile:
$g++ -c main.cpp
$g++ -c Pose.cpp
$g++ -o Pose.o main.o
// Pose.hpp
#include "Vec3f.hh"
#include <vector>
using namespace std;
using std::vector;
class Pose
{
Vec3f root_position;
vector < Vec3f > bonesAngles;
vector < Vec3f > bonesPosition;
public:
void setRootPosition (Vec3f position);
void addBone (Vec3f newBone);
};
//Pose.cpp
#include "Pose.hpp"
using namespace std;
void Pose :: setRootPosition (Vec3f position)
{
root_position = position;
}
void Pose :: addBone (Vec3f newBone)
{
bonesAngles.push_back(newBone);
}
//main.cpp
#include <iostream>
#include "Pose.hpp"
using namespace std;
int main()
{
Pose pose;
Vec3f aux(.2,.3,.4);
pose.addBone(aux);
return 0;
}
I got the error:
/tmp/ccSzsctS.o:main.cpp:function main: error: undefined reference to 'Pose::addBone(Vec3f)'
collect2: erro: ld returned 1 exit status

Answer 1

You must compile a .o file for each .cpp. Try this :
$g++ -c Pose.cpp -o Pose.o
$g++ -c main.cpp -o main.o
$g++ -o Pose.o main.o MyProgram
The .o files are called "object" files, there will contain basically all the information for final compilation. In your case, you need the functions definitions (it's what your compile error says). Compiling as you did only checks that the syntax is correct.
There is 2 steps during compiling : compiling and linking. Compiling (with your command lines) is only checking that the syntax is correct basically. At the end of this step the object files are produced. Linking is using the object files (and possibly other types of files, like .dll, .lib) to create a final product (in your case an executable file, but you can produce many different other things, like .dll, .lib, .a, etc ...).
Understanding compilation is a critical step in programming, I invite you to get into it.
For a more detailed explanation, have a look at : http://www.cs.fsu.edu/~jestes/howto/g++compiling.txt
Good luck !