Expression must be a modifiable lvalue

[ab123]

I have declared

boost::scoped_ptr<ABC> a;

void set_abc(ABC& b){*a = b}

In class ABC i have overloaded = operator.

But this Gives me an error saying expression must be a modifiable lvalue in the set_abc function.

Can some one pls help me why I am getting this error?

[vlad from moscow]

I wonder why are you using boost if you even do not understand the fundamentals of C++?!!!