tr1::reference_wrapper 有什么用?

How is tr1::reference_wrapper useful?(tr1::reference_wrapper 有什么用?)

问题描述

最近我一直在阅读 Scott Meyers 的优秀Effective C++ 书.在最后一个技巧中，他介绍了 TR1 的一些功能 - 我通过 Boost 了解了其中的许多功能.

recently I've been reading through Scott Meyers's excellent Effective C++ book. In one of the last tips he covered some of the features from TR1 - I knew many of them via Boost.

然而，有一个我绝对不认识:tr1::reference_wrapper.

However, there was one that I definitely did NOT recognize: tr1::reference_wrapper.

我将如何以及何时使用 tr1::reference_wrapper?

How and when would I use tr1::reference_wrapper?

推荐答案

据我所知，它就像 boost::ref.基本上，可以复制的参考.在绑定到需要通过引用传递参数的函数时非常有用.

It's like boost::ref, as far as I know. Basically, a reference which can be copied. Very useful when binding to functions where you need to pass parameters by reference.

例如(使用 boost 语法):

For example (using boost syntax):

void Increment( int& iValue )
{
    iValue++;
}

int iVariable = 0;
boost::function< void () > fIncrementMyVariable = boost::bind( &Increment, boost::ref( iVariable ));

fIncrementMyVariable();

这篇 Dr. Dobbs 文章有一些信息.

希望这是正确的，并且有帮助.:)

Hope this is right, and helpful. :)

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