如何TR1 ::的reference_wrapper有用吗？ [英] How is tr1::reference_wrapper useful?

问题描述

最近我一直在通过斯科特迈尔斯的出色 C ++有效的电​​子书阅读。在过去的秘诀之一，他所涵盖的一些功能从TR1 - 我通过升压知道很多。

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.

不过，有一个，我是绝对不承认：TR1 ::的reference_wrapper。

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

如何及何时我会用TR1 ::的reference_wrapper？

How and when would I use tr1::reference_wrapper?

推荐答案

这就像升压::裁判，因为据我所知。基本上，参考其可以被复制。绑定到你需要按引用传递参数的函数时非常有用的。

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（使用升压语法）：

For example (using boost syntax):

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

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

fIncrementMyVariable();

这布斯博士文章，有一些信息。

希望这是正确的，有益的。 ：）

Hope this is right, and helpful. :)

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