C++ Fill a vector with another vector - c++

Question

I have two vectors, and I would like to fill the first one with the second. The vectors are declared like this:
vector<Vec3> firstVector;
Where Vec3 is a struct with float x, y, z.
I have tried liked this with assign:
secondVector.assign(firstVector.begin(), firstVector.end());
But it stops and complains, that there is problem with the end().
I have also tried pushback, but of course it's not working.
As I read before I should do it with assign, but I don't know how to solve it properly.
EDIT:
The error message with insert and assign are the same:
this 0x00000000 ... std::vector > * const
[size] CXX0030: Error: expression cannot be evaluated
[capacity] CXX0030: Error: expression cannot be evaluated
And it points to Visual Studio's vector file to iterator end to the return. With insert it points to iterator begin.
THE CODE:
The first Vector is also part of a struct:
struct o3DModel
{
vector<Vec3> v_Vertices;
};
struct Vec3 {
public:
Vec3() {}
Vec3(float X, float Y, float Z)
{
x = X;
y = Y;
z = Z;
}
float x, y, z;
};
I declare the "o3DModel" struct above in my app class like this and send it to my loader class:
o3DModel *tfTable;
void TheApp::Init()
{
objLoader->ImportOBJ(tfTable, "testcube.obj");
}
The objLoader class, where I successfully fill my "v_Vertices" vector, where "oModel" is the sent "tfTable":
bool OBJLoader::ImportOBJ(o3DModel *oModel, char *strFileName)
{
FillObjData(oModel);
...
return true;
}
void OBJLoader::FillObjData(o3DModel *oModel)
{
oModel->v_Vertices.insert(oModel->v_Vertices.begin(), v_Vertices.begin(), v_Vertices.end());
// This here with insert
outFile2 << oModel->v_Vertices[0].x << "\n";
}
Hope this helps.

Answer 1

If you want secondVector to take on all of the values of firstVector and no others,
secondVector = firstVector;
If you want each of the elements of firstVector to be added to the end secondVector:
secondVector.insert(secondVector.end(),
firstvector.begin(), firstVector.end());
If you want each of the elements of firstVector to be added to the beginning of secondVector:
secondVector.insert(secondVector.begin(),
firstVector.begin(), firstVector.end());

Answer 2

Or if you don't want to do it in the ctor use
secondVector = firstVector

Answer 3

This should work:
vector<Vec3> secondVector(firstVector.begin(), firstVector.end());
That's the case when you're interested in using the vector constructor.

Answer 4

You second vector needs to be declared as a vector of vectors of Vec3 strucs.
vector<vector<Vec3>> secondVector;
secondVector.push_back(firstVector);

Answer 5

Okay, I have solved it, but with a little roundabout. In FillObjData I have created a new Vec3, created an if, gived the first vector x, y, z coordinate to the new Vec3, and pushed the Vec3 into the vector. And when I declared my struct I have declared it real not as a pointer. Now it works perfectly.