Uniform initialization of variables

Classic C++ had some kind of ad-hoc syntax for the initialization of variables. Modern C++ supports uniform initialization (we have already seen examples in the type inference section). The language provides helper classes to developers to support uniform initialization for their custom types:

//----------------Initialization.cpp
#include <iostream>
#include <vector>
#include <initializer_list>
using namespace std;
template <class T>
struct Vector_Wrapper {
    std::vector<T> vctr;
    Vector_Wrapper(std::initializer_list<T> l) : vctr(l) {}
    void Append(std::initializer_list<T> l)
    { vctr.insert(vctr.end(), l.begin(), l.end());}
};
int main() {
    Vector_Wrapper<int> vcw = {1, 2, 3, 4, 5}; // list-initialization
    vcw.Append({6, 7, 8}); // list-initialization in function call

    for (auto n : vcw.vctr) { std::cout << n << ' '; }
    std::cout << '\n';
}

The preceding listing shows how one can enable initialization lists for a custom class created by a programmer.