CODEWITHSUNDEEP
c++stl
jakeoung
jakeoung

Reputation: 207

in STL, how to swap 2 dimension vector

In header file, I declared the following as a public member variable:

vector< vector<unsigned char> > arImage;

In source code, I define temp 

vector<vector<unsigned char> > temp (numImage, vector<unsigned char>(sizeImage));

Now I try to ,

temp.swap(arImage);

But an error occured. (detail errors are omitted because they are not English)

    with
    [
        _Ty=std::vector<unsigned char>
    ]

//////////// Addition,,,,,,,,

I want to swap

    vector<vector<unsigned char> > to vector<vector<unsigned char> >

I'm working with MFC. I can't find proper method, so I actually take another approach.

In header file,

    vector< vector<unsigned char> > * arImage;

In source code,

    arImage = new vector< vector<unsigned char> > (numImage, vector<unsigned char>(sizeImage));

But this approach is not comfortable.(this approach is no error)

I want to use arImage[i][j].

In this approach, I have to use (*arImage)[i][j]

Upvotes: 1

Views: 246

Answers (2)

Mirza Bilal
Mirza Bilal

Reputation: 1050

The thing you are doing wrong here is you are trying to swap vector< unsigned char > with vector of vector< unsigned char > which is not possible.

Vector arImage has items of type unsigned char while temp type is vector<vector<unsigned char> > so temp items are vector<unsigned char>.

So it make sense as can not swap vector<unsigned char> with unsigned char. Similarly you can not swap vector< unsigned char > with vector <vector< unsigned char >>.

I hope it explains everything.

Upvotes: 3

Denis Ermolin
Denis Ermolin

Reputation: 5546

You have to choose index which have to be swaped in your temp:

int index = 0;
temp[index].swap(arImage);

You declared temp as vector of vectors (2D). So swapping will perform with the same type of variable (which is logical). But you try to swap with 1D vector what is wrong, that's what compiler says to you.

Upvotes: 3

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