Thread: Constructor help

Given:-

Code:

class A
{
    public:
        A() { cout << "A constructed\n"}
        A(int i) : x(i) {}

    private:
        int x;
};

int main()
{
    vector < A > temp;

    A();

    temp.push_back(A(3));

    system("pause");
    return 0;
}

What do you mean by invoking the constructor just like that ?
What do you mean by passing the constrctor into the vector temp ?