[libcxx] [test] Mark bits of fs.enum tests as libcpp specific

[mstorsjo]

Summary

The individual enum values in copy_options and file_type aren't specified in the standard.

The standard doesn't require fs::path::format to be a scoped enum.

[ldionne]

LGTM with suggested changes.

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

38–39

Please use LIBCPP_STATIC_ASSERT instead (it is defined in test_macros.h. I'd like to avoid using macros defined in individual stdlibs in the test suite as much as possible.

Also, it would make sense to add a short comment explaining why those are libc++ specific.

[mstorsjo]

Using LIBCPP_STATIC_ASSERT in the changed lines, and added some comments. There's a few cases of existing LIBCPP_ONLY(static_assert()) in other lines nearby that I'm not touching here though.

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

int main(int, char**) {
   typedef std::underlying_type<E>::type UT;
   static_assert(!std::is_convertible<E, UT>::value, "");
 
   LIBCPP_ONLY(static_assert(std::is_same<UT, unsigned short>::value, "")); // Implementation detail
 
   typedef check_bitmask_type<E, E::skip_existing, E::update_existing> BitmaskTester;
   assert(BitmaskTester::check());
 
-  static_assert(
+  // The standard doesn't specify the numeric values of the enum.
+  LIBCPP_STATIC_ASSERT(
           E::none == ME(0),
         "Expected enumeration values do not match");
   // Option group for copy_file
-  static_assert(
+  LIBCPP_STATIC_ASSERT(
           E::skip_existing      == ME(1) &&
           E::overwrite_existing == ME(2) &&
           E::update_existing    == ME(4),
         "Expected enumeration values do not match");
   // Option group for copy on directories
-  static_assert(
+  LIBCPP_STATIC_ASSERT(
           E::recursive == ME(8),
         "Expected enumeration values do not match");
   // Option group for copy on symlinks
-  static_assert(
+  LIBCPP_STATIC_ASSERT(
           E::copy_symlinks == ME(16) &&
           E::skip_symlinks == ME(32),
         "Expected enumeration values do not match");
   // Option group for changing form of copy
-  static_assert(
+  LIBCPP_STATIC_ASSERT(
           E::directories_only    == ME(64) &&
           E::create_symlinks     == ME(128) &&
           E::create_hard_links   == ME(256),
         "Expected enumeration values do not match");
 
   return 0;
 }

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

int main(int, char**) {
   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;
   static_assert(!std::is_convertible<E, UT>::value, "");
 
   LIBCPP_ONLY(static_assert(std::is_same<UT, signed char>::value, "")); // Implementation detail
 
-  static_assert(
+  // The standard doesn't specify the numeric values of the enum.
+  LIBCPP_STATIC_ASSERT(
           E::none == ME(0) &&
           E::not_found == ME(-1) &&
           E::regular == ME(1) &&
           E::directory == ME(2) &&
           E::symlink == ME(3) &&
           E::block == ME(4) &&
           E::character == ME(5) &&
           E::fifo == ME(6) &&
           E::socket == ME(7) &&
           E::unknown == ME(8),
         "Expected enumeration values do not match");
 
   return 0;
 }

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

 #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;
-  static_assert(!std::is_convertible<E, UT>::value, "");
+  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;
 }