iox-1391 Move vocabulary types to separate module

[mossmaurice]

Pre-Review Checklist for the PR Author

1. Code follows the coding style of CONTRIBUTING.md
2. Tests follow the best practice for testing
3. Changelog updated in the unreleased section including API breaking changes
4. Branch follows the naming format (iox-123-this-is-a-branch)
5. Commits messages are according to this guideline
   • Commit messages have the issue ID (iox-#123 commit text)
   • Commit author matches Eclipse Contributor Agreement (and ECA is signed)
6. Update the PR title
   • Follow the same conventions as for commit messages
   • Link to the relevant issue
7. Relevant issues are linked
8. Add sensible notes for the reviewer
9. All checks have passed (except task-list-completed)
10. All touched (C/C++) source code files from iceoryx_hoofs are added to ./clang-tidy-diff-scans.txt
11. Assign PR to reviewer

Notes for Reviewer

• Move optional, expected, variant and string to their own module vocabulary types
  • Remove cxx namespace for those four classes
• Move is_cxx_string type trait out of the general type_traits.hpp into its own file

Checklist for the PR Reviewer

• Commits are properly organized and messages are according to the guideline
• Code according to our coding style and naming conventions
• Unit tests have been written for new behavior
• Public API changes are documented via doxygen
• Copyright owner are updated in the changed files
• All touched (C/C++) source code files from iceoryx_hoofs have been added to ./clang-tidy-diff-scans.txt
• PR title describes the changes

Post-review Checklist for the PR Author

1. All open points are addressed and tracked via issues

References

• Closes Split iceoryx_hoofs into logical modules #1391 (partly)

[codecov]

Codecov Report

Merging #1791 (9a8f14d) into master (f2a4258) will decrease coverage by 0.01%.
The diff coverage is 78.18%.

@@            Coverage Diff             @@
##           master    #1791      +/-   ##
==========================================
- Coverage   75.63%   75.61%   -0.02%     
==========================================
  Files         375      375              
  Lines       14578    14569       -9     
  Branches     2064     2064              
==========================================
- Hits        11026    11017       -9     
+ Misses       2922     2921       -1     
- Partials      630      631       +1     

Flag	Coverage Δ
unittests	75.28% <78.18%> (-0.02%)	⬇️
unittests_timing	15.36% <9.21%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...st/include/iceoryx_dust/internal/cli/arguments.inl	0.00% <0.00%> (ø)
...de/iceoryx_dust/internal/cli/option_definition.hpp	0.00% <ø> (ø)
...clude/iceoryx_dust/internal/cli/option_manager.inl	0.00% <0.00%> (ø)
.../include/iceoryx_dust/posix_wrapper/named_pipe.hpp	100.00% <ø> (ø)
...lude/iceoryx_dust/posix_wrapper/signal_watcher.hpp	0.00% <ø> (ø)
iceoryx_dust/source/cli/command_line_parser.cpp	0.00% <0.00%> (ø)
iceoryx_dust/source/cli/option_definition.cpp	0.00% <0.00%> (ø)
iceoryx_dust/source/cli/option_manager.cpp	0.00% <0.00%> (ø)
...ryx_hoofs/concurrent/resizeable_lockfree_queue.hpp	100.00% <ø> (ø)
...eoryx_hoofs/include/iceoryx_hoofs/cxx/helplets.hpp	96.66% <ø> (ø)
... and 159 more

[elBoberido]

Please fix the links to the expected and optional in how-optional-and-error-values-are-returned-in-iceoryx.md

[mossmaurice]

@elBoberido

Please fix the links to the expected and optional in how-optional-and-error-values-are-returned-in-iceoryx.md

Good catch, done ✔️

[FerdinandSpitzschnueffler]

Looks good but please update ./clang-tidy-diff-scans.txt.

[elBoberido]

Half way through :)

Please do a git checkout master iceoryx_posh and make it compile. This ensures that all symbols are available via the legacy includes.

In general I think having only one base namespace makes the code more readable.

[elBoberido]

Second half done :)

[mossmaurice]

@elBoberido Thanks for the hint!

Please do a git checkout master iceoryx_posh and make it compile. This ensures that all symbols are available via the legacy includes.

This revealed all the places in iceoryx_posh where we implicitly including one of those files 🤦 😁 I'll fix those on a separate PR.

[elBoberido]

Looks good. Almost there

[elBoberido]

I'm wondering a bit when this deprecation warning would be shown. When the cxx namespace will be used? In this case the deprecation message would be wrong

[mossmaurice]

@elBoberido I tried this and had a look very early on when we started with #1391. This will only deprecated what is in exactly this very namespace definition and not everything in cxx :D

[elBoberido]

Okay, tried it out. Deprecating namespaces is a C++17 feature and would indeed print it everywhere where the namespace is used. I think we have to add this comment to the respective using directive :(

[mossmaurice]

@elBoberido Odd, I tried that 🤔 According to cppref it's C++14: https://en.cppreference.com/w/cpp/language/attributes/deprecated

[mossmaurice]

Ah, I might know why it didn't work for you. I just put the comment above because it's so long.. IIRC you have to write:

namespace [[deprecated]] foo
{
  // bla..
}

[elBoberido]

I get this warning from my IDE Attributes on a namespace declaration are a C++17 extension [-Wc++17-extensions] and when compiling with clang but not with gcc

[elBoberido]

Thinking about it, we could use this trick to ensure that we do not break the API. A CI job which builds posh 3.0 against hoofs master and examples 3.0 against posh + hoofs master.

[mossmaurice]

@elBoberido

Thinking about it, we could use this trick to ensure that we do not break the API. A CI job which builds posh 3.0 against hoofs master and examples 3.0 against posh + hoofs master.

IMHO that would be overkill...

[elBoberido]

IMHO that would be overkill...

well, it depends on how serious we are about API breakage 😅

we might not yet be there but at some point I think it would make sense