cpp / latest / io / basic_syncbuf / emit.html /

std::basic_syncbuf<CharT,Traits,Allocator>::emit

bool emit();

Atomically transmits all pending output to the wrapped stream.

All emit() calls transferring characters to the same wrapped stream buffer object appear to execute in a total order, where each emit() call synchronizes-with subsequent emit() calls in that total order, even if these calls are made through difference instances of std::basic_syncbuf/std::basic_osyncstream. In practice, this means that emit() takes a lock uniquely associated with the wrapped stream object: for example, it could be held in a static hash map where the address of the wrapped stream is used as the key.

If a call had been made to sync since the last call to emit(), then also flushes the wrapped stream by calling pubsync() on it.

Parameters

(none).

Return value

true if all of the following is true:

  • there is a wrapped stream (the wrapped streambuf pointer is not null)
  • all characters from the temporary storage were successfully sent into the wrapped stream
  • the call to pubsync(), if requested, also completed successfully.

Returns false otherwise.

Notes

Normally called by the destructor of the owning std::basic_osyncstream or by std::basic_osyncstream::emit.

Example

See also

destroys the basic_osyncstream and emits its internal buffer
(public member function of std::basic_osyncstream<CharT,Traits,Allocator>)
calls emit on the underlying basic_syncbuf to transmit its internal data to the final destination
(public member function of std::basic_osyncstream<CharT,Traits,Allocator>)
constructs a basic_syncbuf object
(public member function)

© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
https://en.cppreference.com/w/cpp/io/basic_syncbuf/emit