basic_istringstream

template <class E,
    class T = char_traits<E>,
    class A = allocator<E> >
    class basic_istringstream : public basic_istream<E, T> {
public:
    explicit basic_istringstream(ios_base::openmode mode = ios_base::in);
    explicit basic_istringstream(const basic_string<E, T, A>& x,
        ios_base::openmode mode = ios_base::in);
    basic_stringbuf<E, T, A> *rdbuf() const;
    basic_string<E, T, A>& str();
    void str(const basic_string<E, T, A>& x);
    };

The template class describes an object that controls extraction of elements and encoded objects from a stream buffer of class basic_stringbuf<E, T, A>, with elements of type E, whose character traits are determined by the class T, and whose elements are allocated by an allocator of class A. The object stores an object of class basic_stringbuf<E, T, A>.