C++ standard does not define the order in which the parameters
passed to a function are evaluated. so in theory, in
```c++
reusable_sst(sst->get_schema(), std::move(sst));
```
`std::move(sst)` could be evaluated before `sst->get_schema`.
but please note, `std::move(sst)` does not move `sst`
away, it merely cast `sst` to a rvalue reference, it is
`reusable_sst()` which *could* move `sst` away by
consuming it. so following call is much more dangerous
than the above one:
```c++
reusable_sst(sst->get_schema(), modify_sst(std::move(sst)))
```
nevertheless, this usage is still confusing. so instead
of passing a copy of `sst` to `reusable_sst`.
this change is inspired by clang-tidy, it warns like:
```
Warning: /home/runner/work/scylladb/scylladb/test/lib/test_services.cc:397:25: warning: 'sst' used after it was moved [bugprone-use-after-move]
397 | return reusable_sst(sst->get_schema(), std::move(sst));
| ^
/home/runner/work/scylladb/scylladb/test/lib/test_services.cc:397:44: note: move occurred here
397 | return reusable_sst(sst->get_schema(), std::move(sst));
| ^
/home/runner/work/scylladb/scylladb/test/lib/test_services.cc:397:25: note: the use and move are unsequenced, i.e. there is no guarantee about the order in which they are evaluated
397 | return reusable_sst(sst->get_schema(), std::move(sst));
|
```
per the analysis above, this is a false alarm.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#18775
86b988a70b