C++17 cleanup: traits replace ::value with _v

[karthikeyann]

• replace std::is_*<T>::value with std::is_*_v<T>

Please suggest any other C++17 tech debts.

[karthikeyann]

rerun tests

[codereport]

LGTM 👍 🔥

[vyasr]

@karthikeyann I believe the failure here is caused by the issue described in #10323. tl;dr merge in the latest branch-22.04 and I think style checks will pass.

[vyasr]

Please suggest any other C++17 tech debts.

Here are some ideas off the top of my head. I'll come back and add to this list later if I think of anything, but other reviewers should feel free to edit this comment and add too. These are definitely out of scope for this PRs and could be added separately; in fact, this comment should probably be converted into a separate issue after we've compiled ideas.

• Use CTAD to get rid of methods like std::make_pair or std::make_unique (make_unique may be a little controversial since it parallels make_shared, which still has advantages over the shared_ptr constructor).
• Use structured bindings instead of std::tie (where possible)
• Add more [[nodiscard]] where appropriate

More complicated changes or changes that require more case-by-case analysis:

• Make more use of std::optional
• Replace SFINAE with if constexpr in cases where the latter is significantly more compact
• Use std::is_invocable to replace lots of complex SFINAE.

[ttnghia]

@karthikeyann You seem to miss std::enable_if 😃

[codecov]

Codecov Report

Merging #10319 (cbb1b8b) into branch-22.04 (a7d88cd) will increase coverage by 0.20%.
The diff coverage is n/a.

@@               Coverage Diff                @@
##           branch-22.04   #10319      +/-   ##
================================================
+ Coverage         10.42%   10.63%   +0.20%     
================================================
  Files               119      122       +3     
  Lines             20603    20953     +350     
================================================
+ Hits               2148     2228      +80     
- Misses            18455    18725     +270     

Impacted Files	Coverage Δ
...ython/custreamz/custreamz/tests/test_dataframes.py	99.39% <0.00%> (-0.01%)	⬇️
python/cudf/cudf/errors.py	0.00% <0.00%> (ø)
python/cudf/cudf/io/orc.py	0.00% <0.00%> (ø)
python/cudf/cudf/_version.py	0.00% <0.00%> (ø)
python/cudf/cudf/datasets.py	0.00% <0.00%> (ø)
python/cudf/cudf/core/frame.py	0.00% <0.00%> (ø)
python/cudf/cudf/core/index.py	0.00% <0.00%> (ø)
python/cudf/cudf/io/parquet.py	0.00% <0.00%> (ø)
python/cudf/cudf/core/series.py	0.00% <0.00%> (ø)
python/cudf/cudf/utils/utils.py	0.00% <0.00%> (ø)
... and 33 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 858ab83...cbb1b8b. Read the comment docs.

[karthikeyann]

@gpucibot merge