[syncstream.osyncstream.overview]

31 Input/output library [input.output]

31.11 Synchronized output streams [syncstream]

31.11.3 Class template basic_osyncstream [syncstream.osyncstream]

31.11.3.1 Overview [syncstream.osyncstream.overview]

namespace std { template<class charT, class traits = char_traits<charT>, class Allocator = allocator<charT>> class basic_osyncstream : public basic_ostream<charT, traits> { public: using char_type = charT; using int_type = traits::int_type; using pos_type = traits::pos_type; using off_type = traits::off_type; using traits_type = traits; using allocator_type = Allocator; using streambuf_type = basic_streambuf<charT, traits>; using syncbuf_type = basic_syncbuf<charT, traits, Allocator>; basic_osyncstream(streambuf_type*, const Allocator&); explicit basic_osyncstream(streambuf_type* obuf) : basic_osyncstream(obuf, Allocator()) {} basic_osyncstream(basic_ostream<charT, traits>& os, const Allocator& allocator) : basic_osyncstream(os.rdbuf(), allocator) {} explicit basic_osyncstream(basic_ostream<charT, traits>& os) : basic_osyncstream(os, Allocator()) {} basic_osyncstream(basic_osyncstream&&) noexcept; ~basic_osyncstream(); basic_osyncstream& operator=(basic_osyncstream&&); void emit(); streambuf_type* get_wrapped() const noexcept; syncbuf_type* rdbuf() const noexcept { return const_cast<syncbuf_type*>(addressof(sb)); } private: syncbuf_type sb; }; }

[Example 1:

A named variable can be used within a block statement for streaming.

{ osyncstream bout(cout); bout << "Hello, "; bout << "World!"; bout << endl; bout << "and more!\n"; } — end example]

[Example 2:

A temporary object can be used for streaming within a single statement.

osyncstream(cout) << "Hello, " << "World!" << '\n';

In this example, cout is not flushed.

— end example]