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.