Whats the significance of return by reference?

Question

In C++,

function() = 10;

works if the function returns a variable by reference.

What are the use cases of it?

Answer 1

You can also achieve method chaining (if you so desire) using return by reference.

class A
{
public:
    A& method1()
    {
        //do something
        return *this;   //return ref to the current object
    }
    A& method2(int i);
    A& method3(float f);  //other bodies omitted for brevity
};

int main()
{
    A aObj;
    aObj.method1().method2(5).method3(0.75);

    //or use it like this, if you prefer
    aObj.method1()
        .method2(5)
        .method3(0.75);
}