C ++ - （*）之间的差异。和 - >？ [英] C++ - Difference between (*). and ->?

问题描述

性能之间或之间有任何差异：

Is there any difference in performance - or otherwise - between:

ptr->a();

和

(*ptr).a(); 

？

推荐答案

因为你在评论中要求它。您可能正在寻找的内容可以在标准（5.2.5类成员访问）中找到：

Since you are asking for it in the comments. What you are probably looking for can be found in the Standard (5.2.5 Class member access):

3如果E1具有类型指向类
X的指针，那么表达式E1-> E2是
转换为等价形式
（*（E1））E2;

3 If E1 has the type "pointer to class X," then the expression E1->E2 is converted to the equivalent form (*(E1)).E2;

编译器将生成完全相同的指令，它将一样有效。你的机器不知道你是否写 - >或*。。

The compiler will produce the exact same instructions and it will be just as efficient. Your machine will not know if you wrote "->" or "*.".

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