Declare array in function call

Question

Right, I KNOW this is possible in C++0x/C++11, and therefore can be done in Visual Studio 2012.

HOWEVER, I am running Visual Studio 2010. I want to know if it is at all possible to do something similar to:

void MyFunction(int myArray[])
{}

MyFunction({1,2,3});

Without the inconvenience of having to declare the array beforehand.

Is there any workaround way of doing this in the version of C++ Visual Studio 2010 uses? Or somehow updating the compiler Visual Studio 2010 uses to support more C++11 features? Or am I out of options?

EDIT:

Thanks to yzt, I have been able to do this with Boost!

Here's some example code in case anyone else happens to be in my position (I don't seem to be able to use a normal array with this, but an std::vector (or indeed another stl container), etc will do just fine!):

The function:

void TestFunction(std::vector<int> myArray)
{
    for(std::vector<int>::size_type i = 0; i < myArray.size(); ++i)
    {
        std::cout<<myArray[i]<<std::endl;
    }
}

Calling it:

TestFunction(boost::assign::list_of(1)(2)(3));

possible duplicate of What C++11 features does Visual Studio 2010 support? — Anthony
– Anthony, Commented Aug 15, 2013 at 22:47
This is not supported in VC11 (VS2012) either, but it is available in VC12 (VS2013 Preview.) — yzt
– yzt, Commented Aug 15, 2013 at 22:50
I seem to remember that Boost had a library for something in this ballpark (assigning to STL containers.) — yzt
– yzt, Commented Aug 15, 2013 at 22:53
I didn't know this. In C#, you can do something like int[] a = new int[]{1, 2, 3};, but not in C++!? — wjmolinam
– wjmolinam, Commented Aug 15, 2013 at 23:00

Jerry Coffin · Accepted Answer · 2013-08-15 23:44:06Z

2

The only version (yet) of Visual C++ to support this directly is the Visual C++ 2013 Preview.

If you're really set on doing this, you can define an vector_builder class that will let you do the job in one line -- with a few provisos: first that it pretty much does have to be a vector instead of an array, and second that the syntax to do the job is quite ugly and counter-intuitive (to the point that I hesitate to even mention it at all).

template<class T>
class make_vector {
    std::vector<T> data;
public:
    make_vector(T const &val) { 
        data.push_back(val);
    }

    make_vector<T> &operator,(T const &t) {
        data.push_back(t);
        return *this;
    }

    operator std::vector<T>() { return data; }
};

template<class T> 
make_vector<T> makeVect(T const &t) { 
    return make_vector<T>(t);
}

With this, you'd call something like:

MyFunction((makeVect(1),2,3));

As I said, this strikes me as ugly enough that I hesitate to mention it at all -- but you may prefer it to the available alternatives.

edited Aug 15, 2013 at 23:44

answered Aug 15, 2013 at 22:58

Jerry Coffin

494k83 gold badges656 silver badges1.2k bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

yzt Over a year ago

I think there is a single extra open parenthesis in your sample usage code (before 1.) It should be ((makeVect(1),2,3)), I believe.

Jim Rhodes Over a year ago

Plus 1 for pointing out how ugly this type of coding style is.

yzt · Accepted Answer · 2013-08-16 12:26:45Z

1

I'm not sure about your exact use case, but you probably can use Boost.Assign to do this. And yes, it does work in VC10.

As has been posted in the comments, one can do like this:

TestFunction(boost::assign::list_of(1)(2)(3));

edited Aug 16, 2013 at 12:26

answered Aug 15, 2013 at 22:56

yzt

9,1231 gold badge38 silver badges47 bronze badges

1 Comment

Interminable Over a year ago

TestFunction(boost::assign::list_of(1)(2)(3)); THANK YOU! :D

Richard Walters · Accepted Answer · 2013-08-15 22:45:17Z

0

Not possible in Visual Studio 2010, or in 2012, for that matter. Sorry!

answered Aug 15, 2013 at 22:45

Richard Walters

1,4748 silver badges16 bronze badges

Comments

Anthony · Accepted Answer · 2013-08-15 22:51:42Z

0

The MSDN page outlining C++11 support in Visual Studio states that initialiser lists are not supported in VC10 or VC11.

edited Aug 15, 2013 at 22:51

answered Aug 15, 2013 at 22:44

Anthony

12.5k10 gold badges72 silver badges107 bronze badges

Collectives™ on Stack Overflow

Declare array in function call

EDIT:

4 Answers 4

2 Comments

1 Comment

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

EDIT:

4 Answers 4

2 Comments

1 Comment

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related