std::basic_syncbuf<CharT,Traits,Allocator>::operator= (3) - Linux Man Pages
basic_syncbuf& operator=(basic_syncbuf&& other);
First, calls emit() to transmit all pending output (and delayed flush, if any) to the wrapped stream.
Then performs move-assignment by moving all contents from other, including the temporary storage, the wrapped stream pointer, policy, and all other state (such as the mutex pointer). After move, other is not associated with a stream, and other.get_wrapped()==nullptr. The put area member pointers of the base class std::basic_streambuf of other are guaranteed to be null. Destroying a moved-from other will not produce any output.
If std::allocator_traits<Allocator>::propagate_on_container_move_assignment::value is false, then the allocator is unchanged. Otherwise, after move-assignment, get_allocator() equals other.get_allocator().
other - another std::basic_syncbuf to move from
This section is incomplete
Reason: no example
operator= (public member function of std::basic_osyncstream<CharT,Traits,Allocator>)
constructor (public member function)
emit (public member function)
swap (public member function)