30 Input/output library [input.output]

30.7 Formatting and manipulators [iostream.format]

30.7.4 Input streams [input.streams]

30.7.4.6 Class template basic_­iostream [iostreamclass]

namespace std {
  template <class charT, class traits = char_traits<charT>>
  class basic_iostream
    : public basic_istream<charT, traits>,
      public basic_ostream<charT, traits> {
  public:
    using char_type   = charT;
    using int_type    = typename traits::int_type;
    using pos_type    = typename traits::pos_type;
    using off_type    = typename traits::off_type;
    using traits_type = traits;

    // [iostream.cons], constructor
    explicit basic_iostream(basic_streambuf<charT, traits>* sb);

    // [iostream.dest], destructor
    virtual ~basic_iostream();

  protected:
    // [iostream.cons], constructor
    basic_iostream(const basic_iostream& rhs) = delete;
    basic_iostream(basic_iostream&& rhs);

    // [iostream.assign], assign and swap
    basic_iostream& operator=(const basic_iostream& rhs) = delete;
    basic_iostream& operator=(basic_iostream&& rhs);
    void swap(basic_iostream& rhs);
  };
}
The class template basic_­iostream inherits a number of functions that allow reading input and writing output to sequences controlled by a stream buffer.

30.7.4.6.1 basic_­iostream constructors [iostream.cons]

explicit basic_iostream(basic_streambuf<charT, traits>* sb);
Effects: Constructs an object of class basic_­iostream, initializing the base class subobjects with basic_­istream<charT, traits>(sb) and basic_­ostream<charT, traits>(sb).
Postconditions: rdbuf() == sb and gcount() == 0.
basic_iostream(basic_iostream&& rhs);
Effects: Move constructs from the rvalue rhs by constructing the basic_­istream base class with move(rhs).

30.7.4.6.2 basic_­iostream destructor [iostream.dest]

virtual ~basic_iostream();
Effects: Destroys an object of class basic_­iostream.
Remarks: Does not perform any operations on rdbuf().

30.7.4.6.3 basic_­iostream assign and swap [iostream.assign]

basic_iostream& operator=(basic_iostream&& rhs);
Effects: As if by swap(rhs).
void swap(basic_iostream& rhs);
Effects: Calls basic_­istream<charT, traits>​::​swap(rhs).