From cppreference.com
std::size_tsize()const;(noexcept since C++11)
(constexpr since C++11)Returns the number of bits that the bitset holds.
Return value
number of bits that the bitset holds, i.e. the template parameter N.
Example
Run this code
#include<bitset>#include<iostream>intmain(){std::cout<<std::bitset<0x400>().size()<<'\n';}Output:
1024 See also
returns the number of bits set to true
(public member function)