Passing a list of numbers to a function in C++ without building array first?

Question

I'm trying to build a function that accepts an array in the following manner:

int inCommon = findCommon({54,56,2,10}, 4);

int findCommon(int nums[], int len){
  for(int i=0; i<len; i++)  cout<<nums[i]<<endl;
  return 1;
}

Note, that's not actually what my function does, but I do loop through the array. I'm just trying to determine if it's possible to pass an array like {54,56,2,10} instead of having to create an array and pass it? (like this:

int theArray[]= {54,56,2,10};
int inCommon = findCommon(theArray,4);

Answer 1

No, I believe {} may only be used to initialize an array.

Answer 2

You need C++0x!

http://en.wikipedia.org/wiki/C%2B%2B0x#Initializer_lists

Answer 3

no. It is impossible. But you can create something like template T* arrayCreator(...) function which will create your array,
Or array wrapper with constructor with unspecified arguments count.
Or create object which will have overloaded operator coma or << and will create your array, findCommon( arrCreator() << 1 << 2 << 3 << 5, other parammeters ) - this method more type safe
Or waiting C++0x implementation.

Answer 4

This is not possible at the time. However, in the next C++ standard C++0x, this will be done using initalizer lists:

int findCommon(std::initializer_list<int> nums)
{
    std::initializer_list<int>::iterator it;
    for (it = nums.begin() ; it != nums.end() ; ++it)
    {
        std::cout << *it << std::endl;  
    }
    return 1;
}

See this presentation from Bjarne Stroustrup, and this article from Wikipedia

If you want to try C++0x features, you can check the last versions of gcc, that supports some of them.

Answer 5

You can do what you want to do using variable argument lists.