How to return an fstream (C++0x)

Question

I think I\'ll get right into it and start with the code:

#include 
#include 
#include 

class test : public std:         


        

Answer 1

The problem is with this:

test(test&& old) {};

This lets you construct a new test from an rvalue test, yes, but it says nothing about your base, which is simply being default constructed (no open file). What you want is this:

test(test&& old) : std::ofstream(std::move(old)) {};

Which will move the stream from old into the base.

Answer 2

I'm going to answer my own question here:

In the GCC C++0x Library Features page, have a look at item 27.9, which reads:

27.9 - File-based streams - Partial - Missing move and swap operations

I guess that's probably the issue I'm having with gcc.

Answer 3

Does the caller need to know that you are returning an ofstream, or would it make more sense to return a streambuf, and let the caller wrap it inside a stream?