幸运的是，这很简单。

如果您使用c++，您应该使用.hpp扩展名，并且您应该使用.h表示C或混合使用C和c++。

使用哪个扩展名并不重要。两种都可以。

我用*.h表示C，用*.hpp表示c++。

你可以随意命名你的include。

只需要在#include中指定全名。

我建议你使用C语言时使用.h，使用c++时使用.hpp。

它最终只是一种惯例。

There is no advantage to any particular extension, other than that one may have a different meaning to you, the compiler, and/or your tools. header.h is a valid header. header.hpp is a valid header. header.hh is a valid header. header.hx is a valid header. h.header is a valid header. this.is.not.a.valid.header is a valid header in denial. ihjkflajfajfklaf is a valid header. As long as the name can be parsed properly by the compiler, and the file system supports it, it's a valid header, and the only advantage to its extension is what one reads into it.

话虽如此，能够基于扩展准确地做出假设是非常有用的，因此对于头文件使用一组易于理解的规则将是明智的。就我个人而言，我更喜欢这样做:

If there are already any established guidelines, follow them to prevent confusion. If all source files in the project are for the same language, use .h. There's no ambiguity. If some headers are compatible with multiple languages, while others are only compatible with a single language, extensions are based on the most restrictive language that a header is compatible with. A header compatible with C, or with both C & C++, gets .h, while a header compatible with C++ but not C gets .hpp or .hh or something of the sort.

This, of course, is but one of many ways to handle extensions, and you can't necessarily trust your first impression even if things seem straightforward. For example, I've seen mention of using .h for normal headers, and .tpp for headers that only contain definitions for templated class member functions, with .h files that define templated classes including the .tpp files that define their member functions (instead of the .h header directly containing both the function declaration and the definition). For another example, a good many people always reflect the header's language in its extension, even when there's no chance of ambiguity; to them, .h is always a C header and .hpp (or .hh, or .hxx, etc.) is always a C++ header. And yet again, some people use .h for "header associated with a source file" and .hpp for "header with all functions defined inline".

考虑到这一点，主要的优势在于始终以相同的风格命名你的头文件，并使这种风格对任何检查你的代码的人来说都很明显。这样，任何熟悉您通常的编码风格的人都可以粗略地看一下，就可以确定您对任何给定扩展的意思。

下面是C和c++头文件命名不同的几个原因:

Automatic code formatting, you might have different guidelines for formatting C and C++ code. If the headers are separated by extension you can set your editor to apply the appropriate formatting automatically Naming, I've been on projects where there were libraries written in C and then wrappers had been implemented in C++. Since the headers usually had similar names, i.e. Feature.h vs Feature.hpp, they were easy to tell apart. Inclusion, maybe your project has more appropriate versions available written in C++ but you are using the C version (see above point). If headers are named after the language they are implemented in you can easily spot all the C-headers and check for C++ versions.

记住，C不是c++，除非你知道你在做什么，否则混合和匹配是非常危险的。适当地命名源代码可以帮助您区分语言。

幸运的是，这很简单。

如果您使用c++，您应该使用.hpp扩展名，并且您应该使用.h表示C或混合使用C和c++。