Overloading << operator C++ - Pointer to Class

Question

class logger {
 ....
};

logger& operator<<(logger& log, const std::string& str)
{
    cout << "My Log: " << str << endl;
    return log;
}

logger log;
log << "Lexicon Starting";

Works fine, but i would like to use a pointer to a class instance instead. i.e.

logger * log = new log();
log << "Lexicon Starting";

Is this possible? If so what is the syntax? Thanks

Edit: The compiler Error is

error: invalid operands of types 'logger*' and 'const char [17]' to binary 'operator<<'

Answer 1

You'd have to dereference the pointer to your logger object and obviously check if it's not 0. Something like this should do the job:

  log && ((*log) << "Lexicon starting")

As a general aside, I would shy away from referencing objects like a logger (which you normally unconditionally expect to be present) via a pointer due to the uncertainty you get with a pointer, AKA is there an object or not?

Answer 2

Here is the way:

logger * log = new log();
(*log) << "Lexicon Starting";