c++模板和头文件 [英] c++ template and header files

问题描述

所以，我听说 C++ 模板不应该分为头文件 (.h) 和源文件 (.cpp).

So, I heard that C++ templates shouldn't be separated into a header (.h) and source (.cpp) files.

例如，这样的模板:

template <class T>
class J
{   
   T something;
};

这是真的吗?为什么会这样?

Is this true? Why is it so?

如果因此我必须将声明和实现放在同一个文件中，我应该将它放在 .h 文件还是 .cpp 文件中?

If because of that I'm gonna have to put both declaration and implementation in the same file, should I put it in a .h file or a .cpp file?

推荐答案

Headers.

这是因为模板是在编译时而不是链接时实例化的，并且不同的翻译单元(大致相当于您的 .cpp 文件)仅在链接时相互了解".标头往往在编译时被广泛了解"，因为您在任何需要它们的翻译单元中#include它们.

It's because templates are instantiated at compile-time, not link-time, and different translation units (roughly equivalent to your .cpp files) only "know about" each other at link-time. Headers tend to be widely "known about" at compile-time because you #include them in any translation unit that needs them.

阅读 https://isocpp.org/wiki/faq/templates 了解更多信息.

Read https://isocpp.org/wiki/faq/templates for more.

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