std::basic_ostream<CharT,Traits>::basic_ostream (3) - Linux Manuals

std::basic_ostream<CharT,Traits>::basic_ostream: std::basic_ostream<CharT,Traits>::basic_ostream


std::basic_ostream<CharT,Traits>::basic_ostream - std::basic_ostream<CharT,Traits>::basic_ostream


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 movable output stream classes std::basic_ofstream and std::basic_ostringstream, which know how to correctly move the associated streambuffer.


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


// Run this code

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

  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::move(std::ostringstream() << 7.1));
      myout << s2.str() << '\n';