ptr->你好();/* 对比 */(*ptr).hello();

问题描述

我正在学习 C++ 指针，而 -> 运算符对我来说似乎很陌生.代替ptr->hello(); 可以写 (*ptr).hello(); 因为它似乎也有效，所以我认为前者只是一个更方便的方式.

I was learning about C++ pointers and the -> operator seemed strange to me. Instead of ptr->hello(); one could write (*ptr).hello(); because it also seems to work, so I thought the former is just a more convenient way.

是这样还是有什么区别?

Is that the case or is there any difference?

推荐答案

-> 运算符 只是语法糖 因为 (*ptr).hello() 是一个PITA 打字.就在 ASM 级别生成的指令而言，没有区别.事实上，在某些语言中(想到 D)，编译器会根据类型计算出所有内容.如果你执行 ptr.hello()，它就可以工作，因为编译器知道 ptr 是一个指针并且没有 hello() 属性，所以你的意思是 (*ptr).hello().

The -> operator is just syntactic sugar because (*ptr).hello() is a PITA to type. In terms of the instructions generated at the ASM level, there's no difference. In fact, in some languages (D comes to mind), the compiler figures everything out based on type. If you do ptr.hello(), it just works, because the compiler knows that ptr is a pointer and doesn't have a hello() property, so you must mean (*ptr).hello().

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