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std::basic_...asic_ostream(3)  C++ Standard Libary std::basic_...asic_ostream(3)

NAME
     std::basic_ostream::basic_ostream - std::basic_ostream::basic_ostream

Synopsis
	explicit basic_ostream( std::basic_streambuf<CharT, Traits>* sb ); (1)
	protected:							     (2)
     (since C++11)
	basic_ostream( const basic_ostream& rhs ) = delete;
	protected:							     (3)
     (since C++11)
	basic_ostream( basic_ostream&& rhs );

	1)  Constructs the basic_ostream object, assigning initial values to the
     base class
	by calling basic_ios::init(sb).
	2) The copy constructor is protected, and is deleted. Output streams are
     not
	copyable.
	3) The move constructor uses basic_ios<CharT, Traits>::move(rhs) to move
     all
	basic_ios members, except for the rdbuf(), from  rhs  into  *this.  This
     move
	constructor  is protected: it is called by the move constructors of mov-
     able output
	stream classes std::basic_ofstream and	std::basic_ostringstream,  which
     know how to
	correctly move the associated streambuffer.

Parameters
	sb  - streambuffer to use as output sequence
	rhs - basic_ostream to initialize from

Notes
	Because  basic_ios::init(sb)  sets badbit when sb is a null pointer, and
     because
	basic_ostream::sentry does nothing if the stream is already in a  failed
     state,
	writing to a stream constructed from a null pointer sb is a no-op.

Example
     // Run this code

      #include <iostream>
      #include <sstream>
      #include <utility>

      int main()
      {
	  // ERROR: copy ctor is deleted
      //  std::ostream myout(std::cout);

	  // OK: shares buffer with cout
	  std::ostream myout(std::cout.rdbuf());

	  // ERROR: move constructor is protected
      //  std::ostream s2(std::move(std::ostringstream() << 7.1));

	  // OK: move ctor called through the derived class
	  std::ostringstream s2(std::ostringstream() << 7.1);
	  myout << s2.str() << '\n';

	  std::ostream dev_null{nullptr}; // see Notes above
	  dev_null << "no-op";
      }

Output:
      7.1

http://cppreference.com 	   2024.06.10	   std::basic_...asic_ostream(3)
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