std::basic_osyncstream<CharT,Traits,Allocator>::operator=

basic_osyncstream& operator=( std::basic_osyncstream&& other );
 (since C++20)

Move-assigns a synchronized output stream:

Move-assigns the wrapped std::basic_syncbuf from the corresponding member of other (after this move-assignment, other.get_wrapped() returns a null pointer and destruction of other produces no output; any pending buffered output will be emitted) and move-assigns the base std::basic_ostream (this swaps all stream state variables except for rdbuf between *this and other)

Parameters

other - another synchronized output stream to move from

Return value

*this

Example

#include <iomanip>
#include <iostream>
#include <sstream>
#include <syncstream>
#include <utility>
 
int main()
{
    std::osyncstream out(std::cout);
    out << "test\n";
    std::ostringstream str_out;
    std::osyncstream{str_out} = std::move(out); // Note that out is emitted here
    std::cout << "str_out = " << std::quoted(str_out.view()) << '\n';
}

Output:

test
str_out = ""

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 3867 C++20 the move assignment operator was noexcept, but
std::basic_syncbuf's move assignment operator is not 		removed noexcept

See also

constructs a basic_osyncstream object
(public member function)
destroys the basic_osyncstream and emits its internal buffer
(public member function)
calls emit() on the underlying basic_syncbuf to transmit its internal data to the final destination
(public member function)

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