27 Input/output library [input.output]

27.8 String-based streams [string.streams]

27.8.5 Class template basic_stringstream [stringstream]

namespace std {
  template <class charT, class traits = char_traits<charT>,
        class Allocator = allocator<charT> >
  class basic_stringstream
    : public basic_iostream<charT,traits> {

    // types:
    typedef charT                     char_type;
    typedef typename traits::int_type int_type;
    typedef typename traits::pos_type pos_type;
    typedef typename traits::off_type off_type;
    typedef traits                    traits_type;
    typedef Allocator                 allocator_type;

    // constructors/destructor
    explicit basic_stringstream(
    ios_base::openmode which = ios_base::out|ios_base::in);
    explicit basic_stringstream(
    const basic_string<charT,traits,Allocator>& str,
    ios_base::openmode which = ios_base::out|ios_base::in);
    basic_stringstream(const basic_stringstream& rhs) = delete;
    basic_stringstream(basic_stringstream&& rhs);

    // [stringstream.assign] Assign/swap:
    basic_stringstream& operator=(const basic_stringstream& rhs) = delete;
    basic_stringstream& operator=(basic_stringstream&& rhs);
    void swap(basic_stringstream& rhs);

    // Members:
    basic_stringbuf<charT,traits,Allocator>* rdbuf() const;
    basic_string<charT,traits,Allocator> str() const;
    void str(const basic_string<charT,traits,Allocator>& str);

    basic_stringbuf<charT, traits> sb;  // exposition only

  template <class charT, class traits, class Allocator>
  void swap(basic_stringstream<charT, traits, Allocator>& x,
            basic_stringstream<charT, traits, Allocator>& y);

The class template basic_stringstream<charT, traits> supports reading and writing from objects of class basic_string<charT, traits, Allocator>. It uses a basic_stringbuf<charT, traits, Allocator> object to control the associated sequence. For the sake of exposition, the maintained data is presented here as

  • sb, the stringbuf object.