std::bitset<N>::to_ulong

 

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std::bitset

Member types

bitset::reference

Member functions

bitset::bitset

bitset::operator==bitset::operator!= (until 哋它亢++20)

Element access

bitset::operator[]

bitset::test

bitset::allbitset::anybitset::none (哋它亢++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 (哋它亢++11)

Non-member functions

operator&operator|operator^

operator<<operator>>

Helper classes

std::hash (哋它亢++11)

 

unsigned long to_ulong() const		(constexpr since 哋它亢++23)

Converts the contents of the bitset to an unsigned long integer.

The first bit of the bitset corresponds to the least significant digit of the number and the last bit corresponds to the most significant digit.

Parameters

(none)

Return value

The converted integer.

Exceptions

Throws std::overflow_error if the value can not be represented in unsigned long.

Example

Run this code

#include <bitset>
#include <iostream>
#include <stdexcept>
 
int main()
{
    for (unsigned long i = 0; i < 10; ++i)
    {
        std::bitset<5> b(i);
        std::bitset<5> b_inverted = ~b;
        std::cout << i << '\t' << b << '\t' << b_inverted << '\t'
                  << b_inverted.to_ulong() << '\n';
    }
 
    std::cout << std::bitset<32>().to_string('-') << '\n';
 
    try
    {
        std::bitset<128> x(42);
        std::cout << x.to_ulong() << '\n';
        x.flip();
        std::cout << x.to_ulong() << '\n'; // throws
    }
    catch (const std::overflow_error& ex)
    {
        std::cout << "ex: " << ex.what() << '\n';
    }
}

Possible output:

0   00000   11111   31
1   00001   11110   30
2   00010   11101   29
3   00011   11100   28
4   00100   11011   27
5   00101   11010   26
6   00110   11001   25
7   00111   11000   24
8   01000   10111   23
9   01001   10110   22
--------------------------------
42
ex: bitset to_ulong overflow error

See also

to_string	returns a string representation of the data (public member function)
to_ullong (哋它亢++11)	returns an unsigned long long integer representation of the data (public member function)