正常
Attribute System
C++ attributes let you pass extra information to the compiler without changing your code's logic — "don't ignore this return value", "this variable may go unused, but don't warn about it", "this branch is more likely to execute"... That information helps you catch bugs, silence unnecessary warnings, and even improve performance. In this chapter we cover the standard attributes from C++11-17 and the new performance-oriented attributes from C++20-23.