Should You Use `endl` in C : Performance vs. Convenience?

The C iostream endl Conundrum

In a recent presentation, renowned programming language designer Andrei Alexandrescu alluded to the "endl" fiasco in C . While endl is commonly used to denote the end of a line and flush a stream's buffer, its excessive usage has sparked controversy.

The Problem

endl adds an unnecessary burden of flushing the stream, which can hinder performance. In most cases, a simple 'n' character suffices to indicate a newline without the need for explicit flushing. Moreover, excessive flushing can introduce unnecessary latency and hinder the program's overall responsiveness.

Why Avoid endl?

• Unnecessary Performance Hit: Flushing the buffer frequently can slow down the program, especially for IO-intensive operations.
• Increased Code Size: endl's inherent flushing functionality results in larger code size than a simple 'n'.
• Dubious Value-Added: In the vast majority of scenarios, 'n' provides sufficient functionality without the performance overhead or code duplication.

When to Use endl

While endl generally falls into the "avoid" category, there are instances where its explicit flushing capability can be beneficial:

• Forcing Immediate Output: In situations where you need immediate display of specific output, endl ensures that the buffer is flushed.
• Delimiting Output: By flushing the buffer, endl helps separate output from different threads or processes.

Conclusion

Despite its common usage, endl should be used sparingly due to its negative impact on performance and code size. For most practical purposes, a simple 'n' newline character provides ample functionality without the unnecessary overhead associated with endl. However, for specific scenarios where explicit flushing is required, endl remains a valuable tool.

The above is the detailed content of Should You Use `endl` in C : Performance vs. Convenience?. For more information, please follow other related articles on the PHP Chinese website!