C ++函数参数:使用引用还是指针(然后取消引用)? [英] C++ function parameters: use a reference or a pointer (and then dereference)?

问题描述

给了我一些代码，其中一些参数是指针，然后将指针取消引用 提供价值.我担心指针取消引用会花费周期，但是在查看之后 以前的StackOverflow文章:取消引用指针?，也许没关系.

I was given some code in which some of the parameters are pointers, and then the pointers are dereferenced to provide values. I was concerned that the pointer dereferencing would cost cycles, but after looking at a previous StackOverflow article: How expensive is it to dereference a pointer?, perhaps it doesn't matter.

以下是一些示例:

bool MyFunc1(int * val1, int * val2)
{
    *val1 = 5;
    *val2 = 10;
    return true;
}

bool MyFunc2(int &val1, int &val2)
{
    val1 = 5;
    val2 = 10;
    return true;
}

就样式而言，我个人更喜欢传递引用，但是一个版本更好 (就过程周期而言)?

I personally prefer the pass-by-reference as a matter of style, but is one version better (in terms of process cycles) than another?

推荐答案

如果参数可以为NULL(即在上述情况下为可选)，则我的经验法则是通过指针传递，如果参数永远不应为NULL，则应进行引用.

My rule of thumb is to pass by pointer if the parameter can be NULL, ie optional in the cases above, and reference if the parameter should never be NULL.

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