initializer_list
#include <iostream>
#include <initializer_list>

int main(int argc, char *argv[])
{
	//initialization
	std::initializer_list<int> l;
	l = {10, 20, 30, 40};

	//size
	std::cout<<"Size: "<<l.size()<<std::endl;

	//access elements
	for(auto e : l)
		std::cout<<e<<" ";
	std::cout<<std::endl;

	for(auto it = l.begin(); it != l.end(); ++it)
		std::cout<<*it<<" ";
	std::cout<<std::endl;

	return 0;
}
			
Reference