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