C++ Bitset Library - none() Function

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Description

The C++ function std::bitset::none() tests whether all bits are unset or not.

Declaration

Following is the declaration for std::bitset::none() function form std::bitset header.

C++98

bool none() const;

C++11

bool none() const noexcept;

Parameters

None

Return value

Returns true if all bits are unset otherwise false.

Exceptions

This member function never throws exception.

Example

The following example shows the usage of std::bitset::none() function.

#include <iostream>
#include <bitset>

using namespace std;

int main(void) {

   bitset<4> b;
   bitset<4> mask("1010");

   if (b.none())
      cout << "All bits are unset." << endl;

   b |= mask;

   if (!b.none())
      cout << "At least one bit set." << endl;

   return 0;
}

Let us compile and run the above program, this will produce the following result −

All bits are unset.
At least one bit set.