[libcxx-commits] [libcxx] [libc++][bitset] Applied `[[nodiscard]]` (PR #170623)

[Thibault Monnier via libcxx-commits]

================
@@ -675,53 +675,62 @@ public:
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bitset& set(size_t __pos, bool __val = true);
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bitset& reset() _NOEXCEPT;
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bitset& reset(size_t __pos);
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bitset operator~() const _NOEXCEPT;
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bitset operator~() const _NOEXCEPT;
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bitset& flip() _NOEXCEPT;
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bitset& flip(size_t __pos);
 
   // element access:
 #  ifdef _LIBCPP_ABI_BITSET_VECTOR_BOOL_CONST_SUBSCRIPT_RETURN_BOOL
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool operator[](size_t __p) const {
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool operator[](size_t __p) const {
     _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__p < _Size, "bitset::operator[] index out of bounds");
     return __base::__make_ref(__p);
   }
 #  else
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR __const_reference operator[](size_t __p) const {
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR __const_reference operator[](size_t __p) const {
     _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__p < _Size, "bitset::operator[] index out of bounds");
     return __base::__make_ref(__p);
   }
 #  endif
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 reference operator[](size_t __p) {
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 reference operator[](size_t __p) {
     _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__p < _Size, "bitset::operator[] index out of bounds");
     return __base::__make_ref(__p);
   }
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long to_ulong() const { return __base::to_ulong(); }
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long to_ullong() const {
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long to_ulong() const {
+    return __base::to_ulong();
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long to_ullong() const {
     return __base::to_ullong();
   }
   template <class _CharT, class _Traits, class _Allocator>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 basic_string<_CharT, _Traits, _Allocator>
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 basic_string<_CharT, _Traits, _Allocator>
   to_string(_CharT __zero = _CharT('0'), _CharT __one = _CharT('1')) const;
   template <class _CharT, class _Traits>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 basic_string<_CharT, _Traits, allocator<_CharT> >
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI
+  _LIBCPP_CONSTEXPR_SINCE_CXX23 basic_string<_CharT, _Traits, allocator<_CharT> >
   to_string(_CharT __zero = _CharT('0'), _CharT __one = _CharT('1')) const;
   template <class _CharT>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 basic_string<_CharT, char_traits<_CharT>, allocator<_CharT> >
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI
+  _LIBCPP_CONSTEXPR_SINCE_CXX23 basic_string<_CharT, char_traits<_CharT>, allocator<_CharT> >
   to_string(_CharT __zero = _CharT('0'), _CharT __one = _CharT('1')) const;
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 basic_string<char, char_traits<char>, allocator<char> >
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI
+  _LIBCPP_CONSTEXPR_SINCE_CXX23 basic_string<char, char_traits<char>, allocator<char> >
   to_string(char __zero = '0', char __one = '1') const;
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 size_t count() const _NOEXCEPT;
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR size_t size() const _NOEXCEPT { return _Size; }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 size_t count() const _NOEXCEPT;
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR size_t size() const _NOEXCEPT { return _Size; }
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool operator==(const bitset& __rhs) const _NOEXCEPT;
----------------
Thibault-Monnier wrote:

Is it the case for `&`, `|`, `^` operators as well?

https://github.com/llvm/llvm-project/pull/170623