Address ldionne's comments

Author: winner245

libcxx/include/bitset

@@ -80,7 +80,7 @@ public:
     constexpr bool operator[](size_t pos) const;
     reference operator[](size_t pos);            // constexpr since C++23
     unsigned long to_ulong() const;              // constexpr since C++23
-    unsigned long long to_ullong() const;        // constexpr since C++23
+    unsigned long long to_ullong() const;        // since C++11, constexpr since C++23
     template <class charT, class traits, class Allocator> // constexpr since C++23
         basic_string<charT, traits, Allocator> to_string(charT zero = charT('0'), charT one = charT('1')) const;
     template <class charT, class traits> // constexpr since C++23
@@ -147,6 +147,7 @@ template <size_t N> struct hash<std::bitset<N>>;
 #  include <__functional/hash.h>
 #  include <__functional/identity.h>
 #  include <__functional/unary_function.h>
+#  include <__tuple/tuple_indices.h>
 #  include <__type_traits/enable_if.h>
 #  include <__type_traits/integral_constant.h>
 #  include <__type_traits/is_char_like_type.h>
@@ -224,12 +225,66 @@ protected:
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void operator^=(const __bitset& __v) _NOEXCEPT;
 
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void flip() _NOEXCEPT;
+
+  // unsigned long spans only one word
+  template <typename _StorageType                                             = __storage_type,
+            __enable_if_t<sizeof(_StorageType) >= sizeof(unsigned long), int> = 0>
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long __to_ulong() const {
+    return static_cast<unsigned long>(__first_[0]);
+  }
+
+  // unsigned long may span multiple words which are concatenated to form the result
+  template <typename _StorageType                                            = __storage_type,
+            __enable_if_t<sizeof(_StorageType) < sizeof(unsigned long), int> = 0>
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long __to_ulong() const {
+    const size_t __ul_words = (sizeof(unsigned long) - 1) / sizeof(__storage_type) + 1;
+    const size_t __n_words  = _N_words < __ul_words ? _N_words : __ul_words;
+    unsigned long __r       = static_cast<unsigned long>(__first_[0]);
+    for (size_t __i = 1; __i < __n_words; ++__i)
+      __r |= static_cast<unsigned long>(__first_[__i]) << (__bits_per_word * __i);
+    return __r;
+  }
+
+  // _Bit_size > sizeof(unsigned long) * CHAR_BIT: overflow check needed
+  template <size_t _Bit_size = _Size, __enable_if_t<(_Bit_size > sizeof(unsigned long) * CHAR_BIT), int> = 0>
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long to_ulong() const {
+    if (auto __e = __make_iter(_Bit_size); std::find(__make_iter(sizeof(unsigned long) * CHAR_BIT), __e, true) != __e)
+      std::__throw_overflow_error("__bitset<_N_words, _Size>::__to_ulong overflow error");
+
+    return __to_ulong();
+  }
+
+  // _Bit_size <= sizeof(unsigned long) * CHAR_BIT: no overflow check needed
+  template <size_t _Bit_size = _Size, __enable_if_t<(_Bit_size <= sizeof(unsigned long) * CHAR_BIT), int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long to_ulong() const {
-    return __to_ulong(_BoolConstant<_Size <= sizeof(unsigned long) * CHAR_BIT>());
+    return __to_ulong();
   }
+
+#  ifndef _LIBCPP_CXX03_LANG
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long to_ullong() const {
-    return __to_ullong(_BoolConstant<_Size <= sizeof(unsigned long long) * CHAR_BIT>());
+    // Check for overflow if _Size does not fit in unsigned long long
+    if _LIBCPP_CONSTEXPR (_Size > sizeof(unsigned long long) * CHAR_BIT) {
+      if (auto __e = __make_iter(_Size);
+          std::find(__make_iter(sizeof(unsigned long long) * CHAR_BIT), __e, true) != __e)
+        std::__throw_overflow_error("__bitset<_N_words, _Size>::__to_ullong overflow error");
+    }
+
+    // At this point, the effective bitset size (excluding leading zeros) fits in unsigned long long
+
+    if _LIBCPP_CONSTEXPR (sizeof(__storage_type) >= sizeof(unsigned long long)) {
+      // If __storage_type is at least as large as unsigned long long, the result spans only one word
+      return static_cast<unsigned long long>(__first_[0]);
+    } else {
+      // Otherwise, the result spans multiple words which are concatenated
+      const size_t __ull_words = (sizeof(unsigned long long) - 1) / sizeof(__storage_type) + 1;
+      const size_t __n_words   = _N_words < __ull_words ? _N_words : __ull_words;
+      unsigned long long __r   = static_cast<unsigned long long>(__first_[0]);
+      for (size_t __i = 1; __i < __n_words; ++__i)
+        __r |= static_cast<unsigned long long>(__first_[__i]) << (__bits_per_word * __i);
+      return __r;
+    }
   }
+#  endif
 
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool all() const _NOEXCEPT { return !__scan_bits(__bit_not()); }
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool any() const _NOEXCEPT {
@@ -259,10 +314,6 @@ private:
       return ~__x;
     }
   };
-#  ifdef _LIBCPP_CXX03_LANG
-  void __init(unsigned long long __v, false_type) _NOEXCEPT;
-  _LIBCPP_HIDE_FROM_ABI void __init(unsigned long long __v, true_type) _NOEXCEPT;
-#  endif // _LIBCPP_CXX03_LANG
 
   template <typename _Proj>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool __scan_bits(_Proj __proj) const _NOEXCEPT {
@@ -281,6 +332,10 @@ private:
     return false;
   }
 
+#  ifdef _LIBCPP_CXX03_LANG
+  void __init(unsigned long long __v, false_type) _NOEXCEPT;
+  _LIBCPP_HIDE_FROM_ABI void __init(unsigned long long __v, true_type) _NOEXCEPT;
+
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long __to_ulong(false_type) const;
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long __to_ulong(true_type) const;
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long __to_ulong(true_type, false_type) const;
@@ -289,11 +344,11 @@ private:
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long __to_ullong(true_type) const;
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long __to_ullong(true_type, false_type) const;
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long __to_ullong(true_type, true_type) const;
-#  if _LIBCPP_STD_VER >= 14
+#  else
   template <size_t... _Indices>
-  _LIBCPP_HIDE_FROM_ABI constexpr __bitset(unsigned long long __v, std::index_sequence<_Indices...>) _NOEXCEPT
+  _LIBCPP_HIDE_FROM_ABI constexpr __bitset(unsigned long long __v, std::__tuple_indices<_Indices...>) _NOEXCEPT
       : __first_{static_cast<__storage_type>(__v >> (_Indices * __bits_per_word))...} {}
-#  endif
+#  endif // _LIBCPP_CXX03_LANG
 };
 
 template <size_t _N_words, size_t _Size>
@@ -325,47 +380,20 @@ inline _LIBCPP_HIDE_FROM_ABI void __bitset<_N_words, _Size>::__init(unsigned lon
 
 #  endif // _LIBCPP_CXX03_LANG
 
-#  ifdef _LIBCPP_CXX03_LANG
 template <size_t _N_words, size_t _Size>
-inline _LIBCPP_CONSTEXPR __bitset<_N_words, _Size>::__bitset(unsigned long long __v) _NOEXCEPT {
+inline _LIBCPP_CONSTEXPR __bitset<_N_words, _Size>::__bitset(unsigned long long __v) _NOEXCEPT
+#  ifndef _LIBCPP_CXX03_LANG
+    : __bitset(__v,
+               std::__make_indices_imp< (_N_words < (sizeof(unsigned long long) - 1) / sizeof(__storage_type) + 1)
+                                            ? _N_words
+                                            : (sizeof(unsigned long long) - 1) / sizeof(__storage_type) + 1,
+                                        0>{})
+#  endif
+{
+#  ifdef _LIBCPP_CXX03_LANG
   __init(__v, _BoolConstant<sizeof(unsigned long long) == sizeof(__storage_type)>());
+#  endif
 }
-#  elif _LIBCPP_STD_VER >= 14
-template <size_t _N_words, size_t _Size>
-inline _LIBCPP_CONSTEXPR __bitset<_N_words, _Size>::__bitset(unsigned long long __v) _NOEXCEPT
-    : __bitset{__v,
-               std::make_index_sequence<
-                   std::min<size_t>(_N_words, (sizeof(unsigned long long) - 1) / sizeof(__storage_type) + 1)>{}} {}
-#  else
-#    if __SIZEOF_LONG_LONG__ <= __SIZEOF_SIZE_T__
-template <size_t _N_words, size_t _Size>
-inline _LIBCPP_CONSTEXPR __bitset<_N_words, _Size>::__bitset(unsigned long long __v) _NOEXCEPT
-    : __first_{static_cast<__storage_type>(__v)} {}
-#    elif __SIZEOF_LONG_LONG__ == 2 * __SIZEOF_SIZE_T__
-template <size_t _N_words, size_t _Size>
-inline _LIBCPP_CONSTEXPR __bitset<_N_words, _Size>::__bitset(unsigned long long __v) _NOEXCEPT
-    : __first_{static_cast<__storage_type>(__v), static_cast<__storage_type>(__v >> __bits_per_word)} {}
-#    elif __SIZEOF_LONG_LONG__ == 4 * __SIZEOF_SIZE_T__
-template <size_t _N_words, size_t _Size, __enable_if_t<_N_words == 2, int> = 0>
-inline _LIBCPP_CONSTEXPR __bitset<_N_words, _Size>::__bitset(unsigned long long __v) _NOEXCEPT
-    : __first_{static_cast<__storage_type>(__v), static_cast<__storage_type>(__v >> __bits_per_word)} {}
-
-template <size_t _N_words, size_t _Size, __enable_if_t<_N_words == 3, int> = 0>
-inline _LIBCPP_CONSTEXPR __bitset<_N_words, _Size>::__bitset(unsigned long long __v) _NOEXCEPT
-    : __first_{static_cast<__storage_type>(__v),
-               static_cast<__storage_type>(__v >> __bits_per_word),
-               static_cast<__storage_type>(__v >> (__bits_per_word * 2))} {}
-
-template <size_t _N_words, size_t _Size, __enable_if_t<_N_words >= 4, int> = 0>
-inline _LIBCPP_CONSTEXPR __bitset<_N_words, _Size>::__bitset(unsigned long long __v) _NOEXCEPT
-    : __first_{static_cast<__storage_type>(__v),
-               static_cast<__storage_type>(__v >> __bits_per_word),
-               static_cast<__storage_type>(__v >> (__bits_per_word * 2)),
-               static_cast<__storage_type>(__v >> (__bits_per_word * 3))} {}
-#    else
-#      error This constructor has not been ported to this platform
-#    endif
-#  endif // _LIBCPP_CXX03_LANG
 
 template <size_t _N_words, size_t _Size>
 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void
@@ -402,70 +430,6 @@ _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void __bitset<_N_words, _Siz
     *__p ^= (__storage_type(1) << __n) - 1;
 }
 
-template <size_t _N_words, size_t _Size>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long
-__bitset<_N_words, _Size>::__to_ulong(false_type) const {
-  if (auto __e = __make_iter(_Size); std::find(__make_iter(sizeof(unsigned long) * CHAR_BIT), __e, true) != __e)
-    std::__throw_overflow_error("bitset __to_ulong overflow error");
-
-  return __to_ulong(true_type());
-}
-
-template <size_t _N_words, size_t _Size>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long
-__bitset<_N_words, _Size>::__to_ulong(true_type) const {
-  return __to_ulong(true_type(), _BoolConstant<sizeof(__storage_type) < sizeof(unsigned long)>());
-}
-
-template <size_t _N_words, size_t _Size>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long
-__bitset<_N_words, _Size>::__to_ulong(true_type, false_type) const {
-  return static_cast<unsigned long>(__first_[0]);
-}
-
-template <size_t _N_words, size_t _Size>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long
-__bitset<_N_words, _Size>::__to_ulong(true_type, true_type) const {
-  const size_t __ul_wrods = (sizeof(unsigned long) - 1) / sizeof(__storage_type) + 1;
-  const size_t __n_words  = _N_words < __ul_wrods ? _N_words : __ul_wrods;
-  unsigned long __r       = static_cast<unsigned long>(__first_[0]);
-  for (size_t __i = 1; __i < __n_words; ++__i)
-    __r |= static_cast<unsigned long>(__first_[__i]) << (__bits_per_word * __i);
-  return __r;
-}
-
-template <size_t _N_words, size_t _Size>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long
-__bitset<_N_words, _Size>::__to_ullong(false_type) const {
-  if (auto __e = __make_iter(_Size); std::find(__make_iter(sizeof(unsigned long long) * CHAR_BIT), __e, true) != __e)
-    std::__throw_overflow_error("bitset __to_ullong overflow error");
-
-  return __to_ullong(true_type());
-}
-
-template <size_t _N_words, size_t _Size>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long
-__bitset<_N_words, _Size>::__to_ullong(true_type) const {
-  return __to_ullong(true_type(), _BoolConstant<sizeof(__storage_type) < sizeof(unsigned long long)>());
-}
-
-template <size_t _N_words, size_t _Size>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long
-__bitset<_N_words, _Size>::__to_ullong(true_type, false_type) const {
-  return static_cast<unsigned long long>(__first_[0]);
-}
-
-template <size_t _N_words, size_t _Size>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long
-__bitset<_N_words, _Size>::__to_ullong(true_type, true_type) const {
-  const size_t __ull_wrods = (sizeof(unsigned long long) - 1) / sizeof(__storage_type) + 1;
-  const size_t __n_words   = _N_words < __ull_wrods ? _N_words : __ull_wrods;
-  unsigned long long __r   = static_cast<unsigned long long>(__first_[0]);
-  for (size_t __i = 1; __i < __n_words; ++__i)
-    __r |= static_cast<unsigned long long>(__first_[__i]) << (__bits_per_word * __i);
-  return __r;
-}
-
 template <size_t _N_words, size_t _Size>
 inline size_t __bitset<_N_words, _Size>::__hash_code() const _NOEXCEPT {
   size_t __h = 0;
@@ -524,8 +488,32 @@ protected:
 
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void flip() _NOEXCEPT;
 
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long to_ulong() const;
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long to_ullong() const;
+  template <size_t _Bit_size = _Size, __enable_if_t<(_Bit_size > sizeof(unsigned long) * CHAR_BIT), int> = 0>
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long to_ulong() const {
+    if (auto __e = __make_iter(_Bit_size); std::find(__make_iter(sizeof(unsigned long) * CHAR_BIT), __e, true) != __e)
+      __throw_overflow_error("__bitset<1, _Size>::to_ulong overflow error");
+
+    return static_cast<unsigned long>(__first_);
+  }
+
+  template <size_t _Bit_size = _Size, __enable_if_t<(_Bit_size <= sizeof(unsigned long) * CHAR_BIT), int> = 0>
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long to_ulong() const {
+    return static_cast<unsigned long>(__first_);
+  }
+
+#  ifndef _LIBCPP_CXX03_LANG
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long to_ullong() const {
+    // If _Size exceeds the size of unsigned long long, check for overflow
+    if _LIBCPP_CONSTEXPR (_Size > sizeof(unsigned long long) * CHAR_BIT) {
+      if (auto __e = __make_iter(_Size);
+          std::find(__make_iter(sizeof(unsigned long long) * CHAR_BIT), __e, true) != __e)
+        __throw_overflow_error("__bitset<1, _Size>::to_ullong overflow error");
+    }
+
+    // If _Size fits or no overflow, directly cast to unsigned long long
+    return static_cast<unsigned long long>(__first_);
+  }
+#  endif
 
   template <bool _Sparse, class _CharT, class _Traits, class _Allocator>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 basic_string<_CharT, _Traits, _Allocator>
@@ -545,19 +533,16 @@ protected:
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool any() const _NOEXCEPT;
 
   _LIBCPP_HIDE_FROM_ABI size_t __hash_code() const _NOEXCEPT;
-
-private:
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long __to_ulong(false_type) const;
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long __to_ulong(true_type) const;
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long __to_ullong(false_type) const;
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long __to_ullong(true_type) const;
 };
 
 template <size_t _Size>
 inline _LIBCPP_CONSTEXPR __bitset<1, _Size>::__bitset() _NOEXCEPT : __first_(0) {}
 
 template <size_t _Size>
 inline _LIBCPP_CONSTEXPR __bitset<1, _Size>::__bitset(unsigned long long __v) _NOEXCEPT
+    // TODO: This is a workaround for a GCC bug causing stage1 CI (generic-gcc, gcc-14, g++-14)
+    // failure due to __bits_per_word lookup failure if not referenced here.
+    // See: https://github.com/llvm/llvm-project/actions/runs/15071518915/job/42368867929?pr=121348#logs
     : __first_(_Size == __bits_per_word ? static_cast<__storage_type>(__v) : static_cast<__storage_type>(__v)) {}
 
 template <size_t _Size>
@@ -583,44 +568,6 @@ inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void __bitset<1, _Siz
   __first_ ^= ~__storage_type(0) >> (__bits_per_word - _Size);
 }
 
-template <size_t _Size>
-inline _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long __bitset<1, _Size>::to_ulong() const {
-  return __to_ulong(_BoolConstant<_Size <= sizeof(unsigned long) * CHAR_BIT>());
-}
-
-template <size_t _Size>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long __bitset<1, _Size>::__to_ulong(false_type) const {
-  if (auto __e = __make_iter(_Size); std::find(__make_iter(sizeof(unsigned long) * CHAR_BIT), __e, true) != __e)
-    __throw_overflow_error("__bitset<1, _Size>::__to_ulong overflow error");
-
-  return static_cast<unsigned long>(__first_);
-}
-
-template <size_t _Size>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long __bitset<1, _Size>::__to_ulong(true_type) const {
-  return static_cast<unsigned long>(__first_);
-}
-
-template <size_t _Size>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long __bitset<1, _Size>::to_ullong() const {
-  return __to_ullong(_BoolConstant<_Size <= sizeof(unsigned long long) * CHAR_BIT>());
-}
-
-template <size_t _Size>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long
-__bitset<1, _Size>::__to_ullong(false_type) const {
-  if (auto __e = __make_iter(_Size); std::find(__make_iter(sizeof(unsigned long long) * CHAR_BIT), __e, true) != __e)
-    __throw_overflow_error("__bitset<1, _Size>::__to_ullong overflow error");
-
-  return static_cast<unsigned long long>(__first_);
-}
-
-template <size_t _Size>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long
-__bitset<1, _Size>::__to_ullong(true_type) const {
-  return static_cast<unsigned long long>(__first_);
-}
-
 template <size_t _Size>
 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool __bitset<1, _Size>::all() const _NOEXCEPT {
   __storage_type __m = ~__storage_type(0) >> (__bits_per_word - _Size);
@@ -683,7 +630,9 @@ protected:
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void flip() _NOEXCEPT {}
 
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long to_ulong() const { return 0UL; }
+#  ifndef _LIBCPP_CXX03_LANG
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long to_ullong() const { return 0ULL; }
+#  endif
 
   template <bool _Sparse, class _CharT, class _Traits, class _Allocator>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 basic_string<_CharT, _Traits, _Allocator>
@@ -794,8 +743,12 @@ public:
     _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;
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long to_ullong() const;
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long to_ulong() const { return __base::to_ulong(); }
+#  ifndef _LIBCPP_CXX03_LANG
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long to_ullong() const {
+    return __base::to_ullong();
+  }
+#  endif
   template <class _CharT, class _Traits, class _Allocator>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 basic_string<_CharT, _Traits, _Allocator>
   to_string(_CharT __zero = _CharT('0'), _CharT __one = _CharT('1')) const;
@@ -931,16 +884,6 @@ _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bitset<_Size>& bitset<_Size>
   return *this;
 }
 
-template <size_t _Size>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long bitset<_Size>::to_ulong() const {
-  return __base::to_ulong();
-}
-
-template <size_t _Size>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long bitset<_Size>::to_ullong() const {
-  return __base::to_ullong();
-}
-
 template <size_t _Size>
 template <class _CharT, class _Traits, class _Allocator>
 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 basic_string<_CharT, _Traits, _Allocator>