std::bitset<N>::set

 

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std::bitset

Member types
bitset::reference
Member functions
bitset::bitset
bitset::operator==bitset::operator!= (until C++20)
Element access
bitset::operator[]
bitset::test
bitset::allbitset::anybitset::none (C++11)
bitset::count
Capacity
bitset::size
Modifiers
bitset::operator&=bitset::operator|=bitset::operator^=bitset::operator~
bitset::operator<<=bitset::operator>>=bitset::operator<<bitset::operator>>
bitset::set
bitset::reset
bitset::flip
Conversions
bitset::to_string
bitset::to_ulong
bitset::to_ullong (C++11)
Non-member functions
operator&operator|operator^	operator<<operator>>
Helper classes
std::hash (C++11)

 

bitset& set();	(1)	(noexcept since C++11) (constexpr since C++23)
bitset& set(std::size_t pos, bool value =true);	(2)	(constexpr since C++23)

Sets all bits to true or sets one bit to specified value.

1) Sets all bits to true.

2) Sets the bit at position pos to the value value.

Parameters

pos	-	the position (counting from ​0​, i.e. from least significant to most significant) of the bit to set
value	-	the value to set the bit to

Return value

*this

Exceptions

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

Example

Run this code

#include <bitset>#include <cstddef>#include <iostream>   int main(){std::bitset<8> b;std::cout<< b <<'\n';std::cout<< b.set()<<'\n';std::cout<< b.reset()<<'\n';   for(std::size_t i =1; i < b.size(); i +=2) b.set(i);   std::cout<< b <<'\n';}

Output:

00000000 11111111 00000000 10101010

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 186	C++98	the type of value was int	corrected to bool
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

See also

reset	sets bits to false (public member function)
flip	toggles the values of bits (public member function)