Is "if (getline(fin, str)) {}" conforming to the C++11 standard?

Question

I checked the C++11 standard and found the following facts:

1. std::getline(fin, str) returns a basic_ios object, whose class has a member function explicit operator bool() const;

2. The class basic_ios doesn't have a member function operator void*() const; as pre-C++11.

So, I think if (getline(fin, str)) {} is not standard conforming. It should be written as

if (bool(getline(fin, str)){}. (However, VC++ 2012 gives a warning on this usage. i.e. force void* to bool)

Am I correct?

Answer 1

The code is conforming. The explicit conversion operator to bool will be called when the object is used as a condition automatically. The change in the standard was meant to maintain that same usage while making it a bit safer.