C和C ++中的翻译单元

Question

Is there a difference between what a translation unit is in C++ and C?

In other posts, I read that a header and source file makes a translation unit, but can a source file alone be called a translation unit in C++ where it contains all the definitions in one file?

Answer 1

A translation unit is not "a header and a source file". It could include a thousand header files (and a thousand source files too).

A translation unit is simply what is commonly known as "a source file" or a ".cpp file" after being preprocessed. If the source file #include s other files the text of those files gets included in the translation unit by the preprocessor. There is no difference between C and C++ on this matter.

Answer 2

Header is added to the .cpp file on preprocessing, so the compilator is basically working on a big chunk of code, containing both .cpp and all of .h added by "#include".

That's the translation unit.

Answer 3

It depends on what you mean by “difference”. Both C and C++ define it similarly: basically, everything that gets compiled when you compile a source file (thus, all of the included headers, expanded macros, etc.). But that's not the same thing in the two languages; things like templates mean that translation units do behave differently in C++ than in C. (C++ has the one definition rule, for example.)

Answer 4

A translation unit is actually what you get once the source and header files have passed through preprocessing (which expands the source using the header files) and precompilation. The compiler uses the translation unit to produce the .obj files that you see in your compiler output directory.

Answer 5

编译器看到的源文件集并作为一个单元进行翻译