[clang-tidy] `misc-const-correctness` false positive

[tearfur]

https://godbolt.org/z/dbKn7dWYz

<source>:8:5: warning: variable 'vz' of type 'size_t' (aka 'unsigned long') can be declared 'const' [misc-const-correctness]
    8 |     size_t vz = static_cast<size_t>(v);
      |     ^
      |            const

If I change the problematic line to auto vz = static_cast<size_t>(v);, the warning goes away.

Current trunk: 1ff7491

[llvmbot]

@llvm/issue-subscribers-clang-tidy

Author: Yat Ho (tearfur)

https://godbolt.org/z/dbKn7dWYz

<source>:8:5: warning: variable 'vz' of type 'size_t' (aka 'unsigned long') can be declared 'const' [misc-const-correctness]
    8 |     size_t vz = static_cast<size_t>(v);
      |     ^
      |            const

If I change the problematic line to auto vz = static_cast<size_t>(v);, the warning goes away.

[tearfur]

P.S. Weird that clang-tidy does not warn modernize-use-auto here.

[firewave]

P.S. Weird that clang-tidy does not warn modernize-use-auto here.

That warning is not enabled by default, so you need to specify it explicitly. If you enable all checks it is being reported:

<source>:8:5: warning: use auto when initializing with a cast to avoid duplicating the type name [hicpp-use-auto,modernize-use-auto]
    8 |     size_t vz = static_cast<size_t>(v);
      |     ^~~~~~
      |     auto

[tearfur]

Yes, of course it's me being stupid again. :) I've hidden my comment to avoid any more confusion.

Still, I think the main issue stands.