CODEWITHSUNDEEP
c++stlvector
Berial
Berial

Reputation: 557

STL cloning a vector

!Hi I have a hard time trying to copy vector of pointers to Point. I have a 

vector<Point*> oldVector

and I want to copy this vector into other vector. So I used a copying constructor. I did this that way

vector<Point*> newVector = vector<Point*>(oldVector.begin(),oldVector.end());

Unfortunately I get an exception/error if I ran this function.

vector interators incompatible

What may be the problem ??

EDIT There must be a bigger problem with iterators, it seems that I can't use iterators at all. I wanted to add two stl vectors into each other so I used wrote sth like this

 vector<int> a, b;
    b.insert(b.end(), a.begin(), a.end());

and I get the sama exception/error during execution of this line

enter image description here

Upvotes: 5

Views: 16713

Answers (5)

wilhelmtell
wilhelmtell

Reputation: 58725

Because the original container is of identical type, std::vector<Point*>, there's no need to use the range constructor; simply use the copy constructor!

std::vector<Point*> newVector(oldVector);

But that's not the main concern here. The main issue here is that of shared pointers. Be very clear with yourself who owns the pointed-at data. Be careful of double-delete!

Upvotes: 1

Mac
Mac

Reputation: 14791

That would be either

vector<Point*> *newVector = new vector<Point*>(oldVector.begin(),oldVector.end());

or

vector<Point*> newVector(oldVector.begin(),oldVector.end());

When creating objects, you only use assignment when allocating from the heap. Otherwise, you simply place the constructor argument(s) inside parentheses after your new variable name.

Alternatively, the following is much simpler:

vector<Point*> newVector(oldVector);

Upvotes: 18

rubenvb
rubenvb

Reputation: 76795

That should work (just tested with std::vector<int>s). There must be some other problem. Does Point have a copy constructor?

Upvotes: 0

Sarfaraz Nawaz
Sarfaraz Nawaz

Reputation: 361792

vector<Point*> newVector = vector<Point*>(oldVector.begin(),oldVector.end());

Why this?

Why not this:

vector<Point*> newVector(oldVector.begin(),oldVector.end());

??. The latter the better!

Even better is this,

vector<Point*> newVector(oldVector);

Upvotes: 1

Bradley Swain
Bradley Swain

Reputation: 814

You want

Vector<Point*> newVector(oldVector.begin(), oldVector.end());

Upvotes: 0

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