结构与类的表现
我想知道是否有使用 g++ -O3 选项对 C++ 中的类和 C 风格结构进行性能比较.是否有任何基准或比较.我一直认为 C++ 类比结构更重，可能也更慢(编译时间对我来说不是很重要，运行时间更重要).我将要实现一个 B 树，为了性能，我应该用类还是用结构来实现它.
I wonder if there are performance comparisons of classes and C style structs in C++ with g++ -O3 option. Is there any benchmark or comparison about this. I've always thought C++ classes as heavier and possibly slower as well than the structs (compile time isn't very important for me, run time is more crucial). I'm going to implement a B-tree, should I implement it with classes or with structs for the sake of performance.
推荐答案
在运行时级别，C++ 中的结构和类之间没有区别.因此，无论您在代码中使用 struct A 还是 class A，都不会产生任何性能差异.
On runtime level there is no difference between structs and classes in C++ at all.
So it doesn't make any performance difference whether you use struct A or class A in your code.
其他的事情是使用一些特性――比如构造函数、析构函数和虚函数――可能会有一些性能损失(但如果你使用它们，你可能仍然需要它们).但是你可以同样成功地在你的类或结构中使用它们.
Other thing, is using some features -- like, constructors, destructors and virtual functions, -- could have some performance penalties (but if you use them you probably need them anyway). But you can with equal success use them both inside your class or struct.
在本文档中，您可以阅读其他C++ 与性能相关的细微之处.
In this document you can read about other performance-related subtleties of C++.
相关文章