运算符重载与函数调用的性能 [英] Performance of operator overloading vs function call

问题描述

让我们假设我创建我自己的向量类如下：

Let us suppose I create my own vector class as follows:

<template class T>
class Vector {
private:
  void** ptr;
  // More functions implementing the custom vector
public:
  T& operator[](int iIndex) const {
    return *(T*)ptr[iIndex];
  }
  T& Item(int iIndex) const {
    return *(T*)ptr[iIndex];
  }
}

假设我有一个 Vector< someClass> v 。严格来说，性能方面，访问向量元素的速度更快。

Let say, I have a Vector<someClass> v. Strictly, performance-wise which of these is faster for accessing an element of the vector.

1. v.Item i）


2. v [i]

1. v.Item(i)
2. v[i]

推荐答案

v [i] 只是 v的语法糖。操作符[]（i）。

性能上没有差异，在所有其他方面相同的名称。

There will be no difference in performance, insofar that there is no difference in performance between two functions with different names that are identical in all other respects.

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