std::bitset<N>::reset

bitset& reset();	(1)	(noexcept since C++11) (constexpr since C++23)
bitset& reset( std::size_t pos );	(2)	(constexpr since C++23)

Sets bits to false.

1) Sets all bits to false

2) Sets the bit at position pos to false.

Parameters

pos

the position of the bit to set

Return value

*this

Exceptions

2) Throws std::out_of_range if pos does not correspond to a valid bit position.

Example

#include <bitset>
#include <iostream>

int main()
{
    std::bitset<8> b(42);
    std::cout << "Bitset is         " << b << '\n';
    b.reset(1);
    std::cout << "After b.reset(1): " << b << '\n';
    b.reset();
    std::cout << "After b.reset():  " << b << '\n';
}

Output:

Bitset is         00101010
After b.reset(1): 00101000
After b.reset():  00000000

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 2250	C++98	the behavior was undefined if `pos` does not correspond to a valid bit position	always throws an exception in this case