vector of class without default constructor

Question

Consider the following class:

Class A
{
    public:
       A() = delete;
       A(const int &x)
       :x(x)
       {}
    private:
       int x;
};

How can one create an std::vector<A> and give an argument to the constructor A::A(const int&)?

Answer 1

How can I create a std::vector of type A and give an argument to A's constructor?

std::vector<A> v1(10, 42);  // 10 elements each with value 42
std::vector<A> v2{1,2,3,4}; // 4 elements with different values

How would I add 3 to the vector?

v.emplace_back(3);          // works with any suitable constructor
v.push_back(3);             // requires a non-explicit constructor

The lack of a default constructor only means you can't do operations that need one, like

vector<A> v(10);
v.resize(20);

both of which insert default-constructed elements into the vector.