[libc++] Always return bool from bitset::operator[](size_t) const

Author: philnik777

libcxx/include/__cxx03/bitset

@@ -612,11 +612,7 @@ public:
  _LIBCPP_HIDE_FROM_ABI bitset& flip(size_t __pos);
 
  // element access:
-#ifdef _LIBCPP_ABI_BITSET_VECTOR_BOOL_CONST_SUBSCRIPT_RETURN_BOOL
  _LIBCPP_HIDE_FROM_ABI bool operator[](size_t __p) const { return __base::__make_ref(__p); }
-#else
- _LIBCPP_HIDE_FROM_ABI __const_reference operator[](size_t __p) const { return __base::__make_ref(__p); }
-#endif
  _LIBCPP_HIDE_FROM_ABI reference operator[](size_t __p) { return __base::__make_ref(__p); }
  _LIBCPP_HIDE_FROM_ABI unsigned long to_ulong() const;
  _LIBCPP_HIDE_FROM_ABI unsigned long long to_ullong() const;

libcxx/include/bitset

@@ -151,6 +151,7 @@ template <size_t N> struct hash<std::bitset<N>>;
 # include <__type_traits/integral_constant.h>
 # include <__type_traits/is_char_like_type.h>
 # include <__utility/integer_sequence.h>
+# include <__utility/unreachable.h>
 # include <climits>
 # include <stdexcept>
 # include <string_view>
@@ -191,15 +192,13 @@ protected:
  static const unsigned __bits_per_word = static_cast<unsigned>(sizeof(__storage_type) * CHAR_BIT);
 
  friend class __bit_reference<__bitset>;
- friend class __bit_const_reference<__bitset>;
  friend class __bit_iterator<__bitset, false>;
  friend class __bit_iterator<__bitset, true>;
  friend struct __bit_array<__bitset>;
 
  __storage_type __first_[_N_words];
 
  typedef __bit_reference<__bitset> reference;
- typedef __bit_const_reference<__bitset> __const_reference;
  typedef __bit_iterator<__bitset, false> __iterator;
  typedef __bit_iterator<__bitset, true> __const_iterator;
 
@@ -209,16 +208,17 @@ protected:
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 reference __make_ref(size_t __pos) _NOEXCEPT {
  return reference(__first_ + __pos / __bits_per_word, __storage_type(1) << __pos % __bits_per_word);
  }
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR __const_reference __make_ref(size_t __pos) const _NOEXCEPT {
- return __const_reference(__first_ + __pos / __bits_per_word, __storage_type(1) << __pos % __bits_per_word);
- }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 __iterator __make_iter(size_t __pos) _NOEXCEPT {
  return __iterator(__first_ + __pos / __bits_per_word, __pos % __bits_per_word);
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 __const_iterator __make_iter(size_t __pos) const _NOEXCEPT {
  return __const_iterator(__first_ + __pos / __bits_per_word, __pos % __bits_per_word);
  }
 
+ _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool __is_set(size_t __pos) const _NOEXCEPT {
+ return __first_[__pos / __bits_per_word] & (__storage_type(1) << __pos % __bits_per_word);
+ }
+
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void operator&=(const __bitset& __v) _NOEXCEPT;
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void operator|=(const __bitset& __v) _NOEXCEPT;
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void operator^=(const __bitset& __v) _NOEXCEPT;
@@ -416,15 +416,13 @@ protected:
  static const unsigned __bits_per_word = static_cast<unsigned>(sizeof(__storage_type) * CHAR_BIT);
 
  friend class __bit_reference<__bitset>;
- friend class __bit_const_reference<__bitset>;
  friend class __bit_iterator<__bitset, false>;
  friend class __bit_iterator<__bitset, true>;
  friend struct __bit_array<__bitset>;
 
  __storage_type __first_;
 
  typedef __bit_reference<__bitset> reference;
- typedef __bit_const_reference<__bitset> __const_reference;
  typedef __bit_iterator<__bitset, false> __iterator;
  typedef __bit_iterator<__bitset, true> __const_iterator;
 
@@ -434,9 +432,6 @@ protected:
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 reference __make_ref(size_t __pos) _NOEXCEPT {
  return reference(&__first_, __storage_type(1) << __pos);
  }
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR __const_reference __make_ref(size_t __pos) const _NOEXCEPT {
- return __const_reference(&__first_, __storage_type(1) << __pos);
- }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 __iterator __make_iter(size_t __pos) _NOEXCEPT {
  // Allow the == case to accommodate the past-the-end iterator.
  _LIBCPP_ASSERT_INTERNAL(__pos <= __bits_per_word, "Out of bounds access in the single-word bitset implementation.");
@@ -448,6 +443,10 @@ protected:
  return __pos != __bits_per_word ? __const_iterator(&__first_, __pos) : __const_iterator(&__first_ + 1, 0);
  }
 
+ _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool __is_set(size_t __pos) const _NOEXCEPT {
+ return __first_ & (__storage_type(1) << __pos);
+ }
+
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void operator&=(const __bitset& __v) _NOEXCEPT;
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void operator|=(const __bitset& __v) _NOEXCEPT;
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void operator^=(const __bitset& __v) _NOEXCEPT;
@@ -556,13 +555,11 @@ protected:
  static const unsigned __bits_per_word = static_cast<unsigned>(sizeof(__storage_type) * CHAR_BIT);
 
  friend class __bit_reference<__bitset>;
- friend class __bit_const_reference<__bitset>;
  friend class __bit_iterator<__bitset, false>;
  friend class __bit_iterator<__bitset, true>;
  friend struct __bit_array<__bitset>;
 
  typedef __bit_reference<__bitset> reference;
- typedef __bit_const_reference<__bitset> __const_reference;
  typedef __bit_iterator<__bitset, false> __iterator;
  typedef __bit_iterator<__bitset, true> __const_iterator;
 
@@ -572,16 +569,17 @@ protected:
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 reference __make_ref(size_t) _NOEXCEPT {
  return reference(nullptr, 1);
  }
- _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR __const_reference __make_ref(size_t) const _NOEXCEPT {
- return __const_reference(nullptr, 1);
- }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 __iterator __make_iter(size_t) _NOEXCEPT {
  return __iterator(nullptr, 0);
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 __const_iterator __make_iter(size_t) const _NOEXCEPT {
  return __const_iterator(nullptr, 0);
  }
 
+ _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool __is_set(size_t) const _NOEXCEPT {
+ std::__libcpp_unreachable();
+ }
+
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void operator&=(const __bitset&) _NOEXCEPT {}
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void operator|=(const __bitset&) _NOEXCEPT {}
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void operator^=(const __bitset&) _NOEXCEPT {}
@@ -618,7 +616,6 @@ public:
  static const unsigned __n_words = _Size == 0 ? 0 : (_Size - 1) / (sizeof(size_t) * CHAR_BIT) + 1;
  typedef __bitset<__n_words, _Size> __base;
  typedef typename __base::reference reference;
- typedef typename __base::__const_reference __const_reference;
 
  // 23.3.5.1 constructors:
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bitset() _NOEXCEPT {}
@@ -680,17 +677,10 @@ public:
  _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 {
  _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__p < _Size, "bitset::operator[] index out of bounds");
- return __base::__make_ref(__p);
+ return __base::__is_set(__p);
  }
-# else
- _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) {
  _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__p < _Size, "bitset::operator[] index out of bounds");
  return __base::__make_ref(__p);

libcxx/test/std/utilities/template.bitset/bitset.members/index_const.pass.cpp

@@ -25,11 +25,7 @@ TEST_CONSTEXPR_CXX23 void test_index_const() {
  assert(v[N / 2] == v.test(N / 2));
  }
  }
-#if !defined(_LIBCPP_VERSION) || defined(_LIBCPP_ABI_BITSET_VECTOR_BOOL_CONST_SUBSCRIPT_RETURN_BOOL)
  ASSERT_SAME_TYPE(decltype(cases[0][0]), bool);
-#else
- ASSERT_SAME_TYPE(decltype(cases[0][0]), typename std::bitset<N>::__const_reference);
-#endif
 }
 
 TEST_CONSTEXPR_CXX23 bool test() {
@@ -47,11 +43,7 @@ TEST_CONSTEXPR_CXX23 bool test() {
  const auto& set = set_;
  auto b = set[0];
  set_[0] = true;
-#if !defined(_LIBCPP_VERSION) || defined(_LIBCPP_ABI_BITSET_VECTOR_BOOL_CONST_SUBSCRIPT_RETURN_BOOL)
  assert(!b);
-#else
- assert(b);
-#endif
 
  return true;
 }