[libc++] Remove noexcept specifier from operator""s

[philnik]

Summary

For some reason operator""s(const char8_t*, size_t) was marked noexcept. Remove it and add regression tests.

[philnik]

• Fix CI

[var-const]

libcxx/include/string

4600

Looks like this patch has unrelated changes?

[philnik]

Fix diff

[philnik]

libcxx/include/string

4600

Yes, thanks!

[huixie90]

LGTM with green CI

[philnik]

• Try to fix CI

[philnik]

• Try to fix CI

libcxx/include/string

 #endif // _LIBCPP_HAS_NO_WIDE_CHARACTERS
 
 template<class _CharT, class _Traits, class _Allocator>
 _LIBCPP_TEMPLATE_DATA_VIS
 const typename basic_string<_CharT, _Traits, _Allocator>::size_type
                basic_string<_CharT, _Traits, _Allocator>::npos;
 
 template <class _CharT, class _Allocator>
 struct __string_hash : public __unary_function<basic_string<_CharT, char_traits<_CharT>, _Allocator>, size_t>
 {
     size_t
     operator()(const basic_string<_CharT, char_traits<_CharT>, _Allocator>& __val) const _NOEXCEPT
     { return __do_string_hash(__val.data(), __val.data() + __val.size()); }
 };
 
 template <class _Allocator>
 struct hash<basic_string<char, char_traits<char>, _Allocator> > : __string_hash<char, _Allocator> {};
#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
     basic_string<wchar_t> operator "" s( const wchar_t *__str, size_t __len )
     {
         return basic_string<wchar_t> (__str, __len);
     }
 #endif
 
 #ifndef _LIBCPP_HAS_NO_CHAR8_T
     inline _LIBCPP_HIDE_FROM_ABI constexpr
-    basic_string<char8_t> operator "" s(const char8_t *__str, size_t __len) _NOEXCEPT
+    basic_string<char8_t> operator "" s(const char8_t *__str, size_t __len)
     {
         return basic_string<char8_t> (__str, __len);
     }
 #endif
 
     inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
     basic_string<char16_t> operator "" s( const char16_t *__str, size_t __len )
     {

libcxx/test/std/strings/basic.string.literals/noexcept.compile.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11
+
+#include <string>
+
+static_assert(!noexcept(std::operator""s(std::declval<const char*>(), std::declval<int>())));
+#ifndef TEST_HAS_NO_CHAR8_T
+static_assert(!noexcept(std::operator""s(std::declval<const char8_t*>(), std::declval<int>())));
+#endif
+static_assert(!noexcept(std::operator""s(std::declval<const char16_t*>(), std::declval<int>())));
+static_assert(!noexcept(std::operator""s(std::declval<const char32_t*>(), std::declval<int>())));
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
+static_assert(!noexcept(std::operator""s(std::declval<const wchar_t*>(), std::declval<int>())));
+#endif

libcxx/test/std/strings/string.classes/typedefs.compile.pass.cpp

 #include <type_traits>
 
 #include "test_macros.h"
 
 static_assert((std::is_same<std::string, std::basic_string<char> >::value), "");
 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
 static_assert((std::is_same<std::wstring, std::basic_string<wchar_t> >::value), "");
 #endif
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
 static_assert((std::is_same<std::u8string, std::basic_string<char8_t> >::value), "");
 #endif
 static_assert((std::is_same<std::u16string, std::basic_string<char16_t> >::value), "");
 static_assert((std::is_same<std::u32string, std::basic_string<char32_t> >::value), "");