Question

With an array you can do this:

int a[] = { 1,2,3,4,5,6 }

How do you do this with a vector?

Answer 1

You could write this, though its not an initialization, but looks very appealing:

std::vector<int> v;
v << 1,2,3,4,5,6,7,8,9,10; //all pushed into the vector!

And to support this syntax, you need two utility operators defined as:

template<typename T>
std::vector<T>& operator << (std::vector<T>& v, const T & item)
{
    v.push_back(item);  return v;
}
template<typename T>
std::vector<T>& operator,(std::vector<T>& v, const T & item)
{
    v.push_back(item);  return v;
}

And you’re done!

Test code:

int main() {
       std::vector<int> v;
       v << 1,2,3,4,5,6,7,8,9,10;

       for ( size_t i = 0 ; i < v.size() ; ++i )
             std::cout << v[i] << " ";
}

Output:

1 2 3 4 5 6 7 8 9 10 

Online demo : http://www.ideone.com/1hyR3

Using the utility operators, you actually can avoid temporary variables such as the one in @Als’s solution, and you can write this without boost!