I was listening to a google talk by Andrei Alexandrescu on the D programming language when he threw out a one liner about the "endl" fiasco. I just thought endl was the preferred way to signify the end of a line and flush the buffer for a stream. Why is it considered a fiasco? Should I not be using it in my code?
Reposting from my comment:
(I assume) He just means that many, especially new, C++ programmers use std::endl blindly instead of '\n' for newline, flushing unnecessarily frequently and potentially making the performance of their program abysmal.
I.e., most people are taught that std::endl is the canonical way to insert a newline into a stream even though it is very rarely necessary or appropriate to flush it.
It is some people's opinion (*cough*) that std::endl shouldn't even be in the standard, as it is so rarely appropriate and not a significant typing savings over '\n' << std::flush anyway.
TL;DR(s):
- In the end,
std::endlbuys you nothing except usually worse performance and usually more typing. - It has its uses, but they are considerably rarer than its frequency of use in most large codebases would suggest, therefore...
- Its utility is highly questionable and its ubiquity is absurd – a fiasco indeed!
来源：https://stackoverflow.com/questions/5492380/what-is-the-c-iostream-endl-fiasco