copying a std::vector to a qvector

Question

I tried copy content of one vector to a QVector using the following

std::copy(source.begin(), source.end(), dest.begin());

However the destination QVector still is empty.

Any suggestions ?

Answer 1

Look at:

std::vector<T> QVector::toStdVector () const

QVector<T> QVector::fromStdVector ( const std::vector<T> & vector ) [static]

From docs

Answer 2

If you are creating a new QVector with the contents of a std::vector you can use the following code as an example:

   std::vector<T> stdVec;
   QVector<T> qVec = QVector<T>::fromStdVector(stdVec);

Answer 3

'fromStdVector' has been explicitly marked deprecated recently. Use following code:

std::vector<...> stdVec;

// ...       

QVector<...> qVec = QVector<...>(stdVec.begin(), stdVec.end());

Answer 4

As the other answers mentioned, you should use the following method to convert a QVector to a std::vector :

std::vector<T> QVector::toStdVector() const

And the following static method to convert a std::vector to a QVector :

QVector<T> QVector::fromStdVector(const std::vector<T> & vector)

Here is an example of how to use QVector::fromStdVector (taken from here ):

std::vector<double> stdvector;
stdvector.push_back(1.2);
stdvector.push_back(0.5);
stdvector.push_back(3.14);

QVector<double> vector = QVector<double>::fromStdVector(stdvector);

Don't forget to specify the type after the second QVector (it should be QVector<double>::fromStdVector(stdvector) , not QVector::fromStdVector(stdvector) ). Not doing so will give you an annoying compiler error.