bitset::count

Returns the number of bits set in the bit sequence.

size_t count( ) const;

Return Value

The number of bits set in the bit sequence.

Example

When compiling this example with the /Wp64 flag or on a 64-bit platform, compiler warning C4267 will be generated. For more information on this warning, see Compiler Warning (level 3) C4267.

// bitset_count.cpp
// compile with: /EHsc
#include <bitset>
#include <iostream>

int main( )
{
    using namespace std;

    bitset<5> b1(4);

    cout << "The collection of bits in the original bitset is: ( "
         << b1 << " )" << endl;

    size_t i;
    i = b1.count();
    cout << "The number of bits in the bitset set to 1 is: "
         << i << "." << endl;

    bitset<5> fb1;
    fb1 = b1.flip();

    cout << "The collection of flipped bits in the modified bitset "
         << "is: ( " << b1 << " )" << endl;

    size_t ii;
    ii = fb1.count();
    cout << "The number of bits in the bitset set to 1 is: "
         << ii << "." << endl;
}

The collection of bits in the original bitset is: ( 00100 )
The number of bits in the bitset set to 1 is: 1.
The collection of flipped bits in the modified bitset is: ( 11011 )
The number of bits in the bitset set to 1 is: 4.

Requirements

Header: <bitset>

Namespace: std

See Also

Reference

bitset Class