The class template
istream_iterator
is an input iterator (
[input.iterators]) that reads successive elements
from the input stream for which it was constructed
.namespace std {
template<class T, class charT = char, class traits = char_traits<charT>,
class Distance = ptrdiff_t>
class istream_iterator {
public:
using iterator_category = input_iterator_tag;
using value_type = T;
using difference_type = Distance;
using pointer = const T*;
using reference = const T&;
using char_type = charT;
using traits_type = traits;
using istream_type = basic_istream<charT,traits>;
constexpr istream_iterator();
constexpr istream_iterator(default_sentinel_t);
istream_iterator(istream_type& s);
istream_iterator(const istream_iterator& x) = default;
~istream_iterator() = default;
istream_iterator& operator=(const istream_iterator&) = default;
const T& operator*() const;
const T* operator->() const;
istream_iterator& operator++();
istream_iterator operator++(int);
friend bool operator==(const istream_iterator& i, default_sentinel_t);
private:
basic_istream<charT,traits>* in_stream;
T value;
};
}