[libcxx-commits] [libcxx] [libc++] Workaround for a bug of overloads in MS UCRT's `<math.h>` (PR #149234)

[Louis Dionne via libcxx-commits]

================
@@ -427,6 +427,23 @@ using std::__math::islessgreater;
 using std::__math::isnan;
 using std::__math::isnormal;
 using std::__math::isunordered;
+#      elif _LIBCPP_STD_VER >= 20
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ldionne wrote:

Minor nit, but I would find this code block easier to read if we did this instead:

```
#ifndef _LIBCPP_MSVCRT
using std::__math::isfinite;
// etc...
#endif

#ifdef _LIBCPP_MSVCRT && _LIBCPP_STD_VER >= 20
using std::__math::__ucrt::isfinite;
// etc...
#endif
```

When looking at the code quickly, a stray `elif _LIBCPP_STD_VER >= 20` makes it look like the initial `#if` uptop was probably a `#if check-for-some-standard-version`, when in reality it's a platform-related check. I find that repeating the platform check makes this clearer.

Just a suggestion, not a requirement.

https://github.com/llvm/llvm-project/pull/149234