Can a variable be initialized with an istream on the same line it is declared? [duplicate]

Answer 1

Maybe not for int, but for your own types:

class MyType {
    int value;
public:
    MyType(istream& is) {
        is >> *this;
    }

    friend istream& operator>>(istream& is, MyType& object);
};  

istream& operator>>(istream& is, MyType& object) {
    return is >> object.value;
}

Then you can create the type with the istream passed to the constructor:

int main() {
    istringstream iss("42");
    MyType object(iss);
}