Question

I am wondering is it okay to return a vector in main()? For example,

aSpecialVectorType main()
{
    aSpecialVectorType xxx(vector::zero);
    // do something here;
    return xxx;
}

Do I need to forward declare “class aSpecialVectorType;” before main()?

And btw, is it legal to use another name other than “main” in c++?

Thanks

Edit1:

If not, what is the best way that it can output a vector?

My friend ask me to give him a blackbox that can serve as “vector in and vector out”, he will use his matlab code to call my code. That’s why I am asking.
I know how to vector in, but not sure if there is an easy way to output a vector.

Thanks

Edit2:

I am surprised why C++ has such an standard, any explanation? 🙂

Answer 1

In C++, main needs to return an int:

C++ standard, 3.6.1.2:

An implementation shall not predefine the main function. This function shall not be overloaded. It shall have a return type of type int, but otherwise its type is implementation-defined.

.

If not, what is the best way that it can output a vector?

To output a vector, you need to copy it to a file or an output stream:

ostream_iterator<int> out_it(cout, ", ");
copy(myvector.begin(), myvector.end(), out_it);

The code fragment above writes the content of vector<int> to the standard output.