I noticed that in cppreference/bitset, bitset is not mentioned to be inherited from _ Base_bitset , including the following header file.

Does the cppreference estimate omit this inheritance relationship?

namespace std {
  template<size_t N> class bitset {
  public:
    // bit reference
    class reference {
      friend class bitset;
      reference() noexcept;
 
    public:
      reference(const reference&) = default;
      ~reference();
      reference& operator=(bool x) noexcept;            // for b[i] = x;
      reference& operator=(const reference&) noexcept;  // for b[i] = b[j];
      bool operator~() const noexcept;                  // flips the bit
      operator bool() const noexcept;                   // for x = b[i];
      reference& flip() noexcept;                       // for b[i].flip();
    };
 
    // constructors
    constexpr bitset() noexcept;
    constexpr bitset(unsigned long long val) noexcept;
    template<class CharT, class Traits, class Allocator>
      explicit bitset(
        const basic_string<CharT, Traits, Allocator>& str,
        typename basic_string<CharT, Traits, Allocator>::size_type pos = 0,
        typename basic_string<CharT, Traits, Allocator>::size_type n
          = basic_string<CharT, Traits, Allocator>::npos,
        CharT zero = CharT('0'),
        CharT one = CharT('1'));
    template<class CharT>
      explicit bitset(
        const charT* str,
        typename basic_string<CharT>::size_type n = basic_string<CharT>::npos,
        CharT zero = CharT('0'),
        CharT one = CharT('1'));
 
    // bitset operations
    bitset& operator&=(const bitset& rhs) noexcept;
    bitset& operator|=(const bitset& rhs) noexcept;
    bitset& operator^=(const bitset& rhs) noexcept;
    bitset& operator<<=(size_t pos) noexcept;
    bitset& operator>>=(size_t pos) noexcept;
    bitset& set() noexcept;
    bitset& set(size_t pos, bool val = true);
    bitset& reset() noexcept;
    bitset& reset(size_t pos);
    bitset  operator~() const noexcept;
    bitset& flip() noexcept;
    bitset& flip(size_t pos);
 
    // element access
    constexpr bool operator[](size_t pos) const;        // for b[i];
    reference operator[](size_t pos);                   // for b[i];
 
    unsigned long to_ulong() const;
    unsigned long long to_ullong() const;
    template<class CharT = char,
             class Traits = char_Traits<CharT>,
             class Allocator = allocator<CharT>>
      basic_string<CharT, Traits, Allocator>
        to_string(CharT zero = CharT('0'), CharT one = CharT('1')) const;
 
    size_t count() const noexcept;
    constexpr size_t size() const noexcept;
    bool operator==(const bitset& rhs) const noexcept;
    bool test(size_t pos) const;
    bool all() const noexcept;
    bool any() const noexcept;
    bool none() const noexcept;
    bitset operator<<(size_t pos) const noexcept;
    bitset operator>>(size_t pos) const noexcept;
  };
 
  // hash support
  template<class T> struct hash;
  template<size_t N> struct hash<bitset<N>>;
}

CodePudding user response：

The description of std::bitset can be found in the C Standard at 22.9 Utilities.bitset.

It doesn't mention _Base_bitset or other details, because those are left to the library implementors.

CodePudding user response：

The synopsis for std::bitset is as follows. The rest are implementation details that are irrelevant may change, and should not affect well-formed code.

namespace std 
{
template<size_t N> class bitset;
 
template<size_t N> bitset<N> operator&(const bitset<N>&, const bitset<N>&) noexcept;
template<size_t N> bitset<N> operator|(const bitset<N>&, const bitset<N>&) noexcept;
template<size_t N> bitset<N> operator^(const bitset<N>&, const bitset<N>&) noexcept;
template<class CT, class T, size_t N> basic_istream<CT, T>& operator>>(basic_istream<CT, T>& is, bitset<N>& x);
template<class CT, class T, size_t N> basic_ostream<CT, T>& operator<<(basic_ostream<CT, T>& os, const bitset<N>& x);
}