C ++中的前后递增/递减运算符在循环中具有相同的性能吗？ [英] Does Pre and post increment/decrement operators in C++ have same performance in a loop?

问题描述

请考虑以下两个例子。

class ClassOne
{
 //class definition is here
};

std::vector< ClassOne > myListOfObjects;

std::vector< ClassOne >::const_iterator iter = myListOfObjects.begin();

Example 1: 
for( ; iter < myListOfObjects.end(); **++iter**)
{
   //some operations
}

OR

Example 2: 
for( ; iter < myListOfObjects.end(); **iter++**)
{
   //some operations
}

哪一个更快？ ++ iter或iter ++在循环的上下文中。

Which one is faster ? ++iter or iter++ in the context of loop.

从Brian的帖子

您也可以尝试以下类似问题之一：此处或此处或此处或此处。

You could also try one of these similar questions: here or here or here or here.

推荐答案

如 this answer ，pre更快。它们只有在处理原语（int，char等）时才是相同的。在这种情况下，他们调用重载运算符。

As noted in this answer, pre is faster. They are only the same when you are dealing with primitives (int, char, etc.). In this case, they are calling overloaded operators.

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