std::bitset<N>::count
std::size_t count() const; |
(until C++11) | |
std::size_t count() const noexcept; |
(since C++11) | |
Returns the number of bits that are set to true.
Parameters
(none)
Return value
number of bits that are set to true.
Example
Run this code
#include <iostream> #include <bitset> int main() { std::bitset<8> b("00010010"); std::cout << "initial value: " << b << '\n'; // find the first unset bit std::size_t idx = 0; while (idx < b.size() && b.test(idx)) ++idx; // continue setting bits until half the bitset is filled while (idx < b.size() && b.count() < b.size()/2) { b.set(idx); std::cout << "setting bit " << idx << ": " << b << '\n'; while (idx < b.size() && b.test(idx)) ++idx; } }
Output:
initial value: 00010010 setting bit 0: 00010011 setting bit 2: 00010111
See also
returns the size number of bits that the bitset can hold (public member function) |