[libcxx-commits] [libcxx] [libc++] Fix possible out of range access in bitset (PR #121348)

[Louis Dionne via libcxx-commits]

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@@ -233,12 +237,19 @@ private:
   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
-  _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;
-  _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;
+  _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;
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long __to_ulong(true_type, 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;
+  _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
+  template <size_t... _Indices>
+  _LIBCPP_HIDE_FROM_ABI constexpr __bitset(unsigned long long __v, std::index_sequence<_Indices...>) _NOEXCEPT
----------------
ldionne wrote:

I think you can use `__integer_sequence` in all standard modes instead: https://github.com/llvm/llvm-project/blob/main/libcxx/include/__utility/integer_sequence.h#L26

I would introduce `__make_integer_sequence` that does the right thing and have `std::make_integer_sequence` be an alias to it. And then I'd use `__make_integer_sequence` from here.

https://github.com/llvm/llvm-project/pull/121348