Currently, I program in Java and use Maven quite a bit. As so I’ve become accustom to the naming schemes and folder structures that I’ve used over the past 4 or 5 years.
As I have recently started to learn C++, I’m realizing that I have no idea where to put all my files. Should I keep everything broken down by namespace, or by what tier it is in? Where, for example, would I keep a series of files devoted to UI, as apposed to files meant to help store data?
Are there any standards for this sort of thing?
Clearly, there is no definitive answer to this question. I’m simply looking for a good guide. I do not want to start learning C++ by spending too much time worrying about how my files are laid out. I’d rather have some good models, and just get to the coding.
The following is fairly typical…
Basically, subfolders for subprojects is common for larger projects, but mostly a particular project has folders for src, include etc. A folder for each build configuration is common, and keeping the obj files and other intermediates in a subfolder of that is a good idea. It may be tempting to put subproject folders in obj folders, but usually that’s unnecessary – the obj folders don’t need to be well organised, so the only concern is a filename conflict, and the best fix for that is to have unique source filenames within (at least) each project.
The “include” folders should IMO only contain headers that will be #included by other projects – internal headers belong in the “src” folder.
Putting UI stuff in a separate folder isn’t a bad idea, if it’s big enough. I’ve seen UI stuff done as a separate static-linked top-level project, and I do mean app-specific here, not (e.g.) wxWidgets. Usually, though, that level of division is sub-project if it’s worth separating at all. How you divide subprojects is more a matter of application-specific blocks in general, so it depends on whether UI stuff is best handled as a separate block or as separate chunks mixed in with task-specific logic.
Namespaces aren’t the most used language feature, possibly because a lot of people use “using” so much they don’t make much difference. A namespace for a main library project makes sense, but associating subfolders to namespaces 1:1 isn’t something I’ve seen. I personally have a namespace that encompasses most of my library code, with a couple of sub-namespaces for things rarely used in general, but used a lot in a few places (e.g. a “bitwise” namespaces). The sub-namespaces are limited to single source/header pairs, so no need for subfolders. Most of the library-specific selection is done by including the right header – except that I usually include the lot through a main-project top-level header anyway.
Basically, namespaces are a way of avoiding naming conflicts. They don’t necessarily associate with abstractions or functional blocks or anything. Within a particular project, you’re probably better off just making sure the names don’t conflict. As with the “std” namespace, it’s fine to put a lot of stuff in one namespace.
As you say, though, this isn’t a definitive answer – there are of course minor variations and quite different approaches.