C++ programming style

Question

I\'m an old (but not too old) Java programmer, that decided to learn C++. But I have seen that much of C++ programming style, is... well, just damn ugly!

All that stuff

Answer 1

When the code builds, the C++ preprocessor builds a translation unit. It starts with a .cpp file, parses the #includes grabbing the text from the headers, and generates one great big text file with all the headers and the .cpp code. Then this translation unit gets compiled into code that will run on the platform you're targeting. Each translation unit ends up as one object file.

So, .h files get included in multiple translation units, and a .cpp file just gets included in one.

If .h files contain lots of stuff (including implementation), then the translation units would be correspondingly bigger. Compile times would increase, and when you change anything in a header... every translation unit that uses it would need to be recompiled.

So.. minimizing stuff in .h files drastically improves compile time. You can edit a .cpp file to change a function, and only that one translation unit needs to be rebuilt.

To complete the story on compiling...
Once all the translation units are build into object files (native binary code for you platform). The linker does its job, and stitches them together into you .exe, .dll or .lib file. A .lib file can be linked into another build so it can be reused in more than one .exe or .dll.

I suppose the Java compilation model is more advanced, and the implications of where you put your code have less meaning.