[libcxx] Make path::format a non-class enum

[mstorsjo]

Summary

The spec doesn't declare it as an enum class (as far as I can read the spec - hopefully someone can doublecheck my reading of it), and being declared as an enum class breaks referring to the values as e.g. path::auto_format.

[ldionne]

I think they certainly missed an opportunity to make it an enum class, but you seem to be right.

Ship it with the comment removed.

libcxx/test/std/input.output/filesystems/fs.enum/enum.path.format.pass.cpp

25–26

I don't think this comment applies anymore.

[mstorsjo]

Rerun CI

libcxx/include/filesystem

#if defined(_LIBCPP_WIN32API)
   static constexpr value_type preferred_separator = L'\\';
 #else
   typedef char value_type;
   static constexpr value_type preferred_separator = '/';
 #endif
   typedef basic_string<value_type> string_type;
   typedef basic_string_view<value_type> __string_view;
 
-  enum class _LIBCPP_ENUM_VIS format : unsigned char {
+  enum _LIBCPP_ENUM_VIS format : unsigned char {
     auto_format,
     native_format,
     generic_format
   };
 
   // constructors and destructor
   _LIBCPP_INLINE_VISIBILITY path() noexcept {}
   _LIBCPP_INLINE_VISIBILITY path(const path& __p) : __pn_(__p.__pn_) {}

libcxx/test/std/input.output/filesystems/class.path/path.member/path.construct/source.pass.cpp

 }
 
 template <class CharT, class ...Args>
 void RunTestCase(MultiStringType const& MS) {
   RunTestCaseImpl<CharT>(MS);
   RunTestCaseImpl<CharT>(MS, fs::path::format::auto_format);
   RunTestCaseImpl<CharT>(MS, fs::path::format::native_format);
   RunTestCaseImpl<CharT>(MS, fs::path::format::generic_format);
+  RunTestCaseImpl<CharT>(MS, fs::path::auto_format);
+  RunTestCaseImpl<CharT>(MS, fs::path::native_format);
+  RunTestCaseImpl<CharT>(MS, fs::path::generic_format);
 }
 
 void test_sfinae() {
   using namespace fs;
   {
     using It = const char* const;
     static_assert(std::is_constructible<path, It>::value, "");
   }

libcxx/test/std/input.output/filesystems/fs.enum/enum.path.format.pass.cpp

 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 
 int main(int, char**) {
   typedef fs::path::format E;
   static_assert(std::is_enum<E>::value, "");
 
-  // Check that E is a scoped enum by checking for conversions.
   typedef std::underlying_type<E>::type UT;
-  LIBCPP_STATIC_ASSERT(!std::is_convertible<E, UT>::value, "");
 
   LIBCPP_ONLY(static_assert(std::is_same<UT, unsigned char>::value, "")); // Implementation detail
 
   static_assert(
           E::auto_format   != E::native_format &&
           E::auto_format   != E::generic_format &&
           E::native_format != E::generic_format,
         "Expected enumeration values are not unique");
 
   return 0;
 }