pImpl成语是否真的在实践中使用？ [英] Is the pImpl idiom really used in practice?

问题描述

我正在阅读Herb Sutter的书Exceptional C ++，在那本书中我学到了pImpl的用法。基本上，这个想法是为类的 private 对象创建一个结构，并动态分配给减少编译时间（并以更好的方式隐藏私有实现）。

I am reading the book "Exceptional C++" by Herb Sutter, and in that book I have learned about the pImpl idiom. Basically, the idea is to create a structure for the private objects of a class and dynamically allocate them to decrease the compilation time (and also hide the private implementations in a better manner).

例如：

class X
{
private:
  C c;
  D d;  
} ;

可以更改为：

class X
{
private:
  struct XImpl;
  XImpl* pImpl;       
};

，在CPP中，定义如下：

and, in the CPP, the definition:

struct X::XImpl
{
  C c;
  D d;
};

这似乎很有趣，但我从来没有见过这种方法，已经工作，也没有在开源项目中我看到源代码。所以，我想知道这种技术是真正在实践中使用吗？

This seems pretty interesting, but I have never seen this kind of approach before, neither in the companies I have worked, nor in open source projects that I've seen the source code. So, I am wondering it this technique is really used in practice?

我应该使用它无处不在，还是小心？这种技术推荐用于嵌入式系统（性能非常重要）。

Should I use it everywhere, or with caution? And is this technique recommended to be used in embedded systems (where the performance is very important)?

推荐答案

所以，我想知道这种技术是真正在实践中使用吗？

So, I am wondering it this technique is really used in practice? Should I use it everywhere, or with caution?

当然，它被使用，在我的项目中，几乎在每个类中，您提到的几个原因：

Of course it is used, and in my project, in almost every class, for several reasons you mentioned :

• 数据隐藏


• 重新编译时间确实减少，文件需要重建，而不是头文件和包含它的每个文件


• 二进制兼容性。由于类声明没有改变，只更新库是安全的（假设您正在创建库）

这种技术推荐用于嵌入式系统（性能非常重要）？

is this technique recommended to be used in embedded systems (where the performance is very important)?

你的目标是多么强大。但是，这个问题的唯一答案是：测量和评估你获得和失去的。

That depends on how powerful your target is. However the only answer to this question is : measure and evaluate what you gain and lose.

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