c++ - Is the move constructor of ifsteam implicitly deleted?

Question

I have the following simple class:

class Source
{
public:
    Source() = default;
    Source(Source const&) = delete;
    Source(Source&&) = default;

    explicit Source(std::string const& fileName)
     : inputStream(fileName), path_(fileName)
    {}

    ~Source() = default;

    auto path() const -> std::string
    {
        return this->path_;
    }

    std::ifstream inputStream;
private:
    std::string path_;
};

auto main(int argc, char* argv[]) -> int
{
    Source source(Source("test.txt"));
    cout << source.path() << "
";

    return 0;
}

According to cppreference ifstream has a move constructor, but when I try to compile that with MinGW 4.7.2, I get the following error:

..srcmain.cpp:32:46: error: use of deleted function 'cy::Source::Source(cy::Source&&)' In file included from ..srcmain.cpp:10:0: source.hpp:28:5: note: 'cy::Source::Source(cy::Source&&)' is implicitly deleted because the default definition would be ill-formed: source.hpp:28:5: error: use of deleted function 'std::basic_ifstream::basic_ifstream(const std::basic_ifstream&)' c:mingwin../lib/gcc/mingw32/4.7.2/include/c++/fstream:420:11: note: 'std::basic_ifstream::basic_ifstream(const std::basic_ifstream&)' is implicitly deleted because the default definition would be ill-formed: c:mingwin../lib/gcc/mingw32/4.7.2/include/c++/fstream:420:11: error: use of deleted function 'std::basic_istream::basic_istream(const std::basic_istream&)'

Am I doing something wrong? Or the documentation of cppreference is inaccurate? Or GCC 4.7.2 has a bug?

Answer 1

It turns out that the standard library implementation of GCC has not implemented yet the move and swap operation for the stream classes. See here for detail about the current status of C++11 features in the gcc standard library.

Thanks Jesse Good for giving the information and link.