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

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< cpp‎ | io‎ | basic ostream

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

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.

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

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

Output:

    7.1

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