30 Input/output library [input.output]

30.8 String-based streams [string.streams]

30.8.5 Class template basic_­stringstream [stringstream]

30.8.5.1 basic_­stringstream constructors [stringstream.cons]

explicit basic_stringstream( ios_base::openmode which = ios_base::out | ios_base::in);
Effects: Constructs an object of class basic_­stringstream<charT, traits>, initializing the base class with basic_­iostream<charT, traits>(&sb) ([iostream.cons]) and initializing sb with basic_­stringbuf<charT, traits, Allocator>(which).
explicit basic_stringstream( const basic_string<charT, traits, Allocator>& str, ios_base::openmode which = ios_base::out | ios_base::in);
Effects: Constructs an object of class basic_­stringstream<charT, traits>, initializing the base class with basic_­iostream<charT, traits>(&sb) ([iostream.cons]) and initializing sb with basic_­stringbuf<charT, traits, Allocator>(str, which).
basic_stringstream(basic_stringstream&& rhs);
Effects: Move constructs from the rvalue rhs.
This is accomplished by move constructing the base class, and the contained basic_­stringbuf.
Next basic_­istream<charT, traits>​::​set_­rdbuf(&sb) is called to install the contained basic_­stringbuf.