std::bitset<N>::size
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                    |   std::size_t size() const;  | 
(until C++11) | |
|   constexpr std::size_t size() const noexcept;  | 
(since C++11) | |
Returns the number of bits that the bitset can hold.
Parameters
(none)
Return value
number of bits that the bitset can hold, i.e. the template parameter N
See also
|    returns the number of bits set to true  (public member function)  |