sync ostream buffer after whole json write finished

[Shadasviar]

I have a custom socket implementation, which inherits from streambuf and iostream, so I can use it with nlohmann::json like below:

Socket s("/tmp/out");
nlohmann::json json = ... /*some valid json here*/
s << json;
s.flush();

As you can see from example code, I always need to call streambuf flush method after json was written to the socket, because nlohmann library doesn't call it inside.

Of course, I can implement putc function of my buffer such way, so it would call sync and perform write system call for every char/only for end of line character, but I think that it would be good if nlohmann library would call sync function on output streambuf it use after json was put to buffer, because library knows when json ends. Such behavior could save a lot of write system calls and user should not to call flush manually.

I would want to discuss, if adding syncing buffer to the nlohmann library is a good or bad idea, does it have some drawbacks etc.

[nlohmann]

I understand the issue, but I am not sure whether the library should decide when to flush - I think this is something an application can better decide. In your case, you could create a function that wraps the streaming/flushing. In a general case, the use case may dictate different strategies - maybe it's perfectly fine to never flush.