For each
istreambuf_iterator constructor in this section,
an end-of-stream iterator is constructed if and only if
the exposition-only member
sbuf_ is initialized with a null pointer value
. constexpr istreambuf_iterator() noexcept;
Effects:
Initializes
sbuf_ with
nullptr. istreambuf_iterator(istream_type& s) noexcept;
Effects:
Initializes
sbuf_ with
s.rdbuf(). istreambuf_iterator(streambuf_type* s) noexcept;
Effects:
Initializes
sbuf_ with
s. istreambuf_iterator(const proxy& p) noexcept;
Effects:
Initializes
sbuf_ with
p.sbuf_.