bitset rotational shift?

[PengYu.UT]

I need to do rotational shift on bitset. But I couldn't find that
operation in the standard. Is there any workaround or other packages to
do this?

Thanks,
Peng

 

[Howard Hinnant]

I need to do rotational shift on bitset. But I couldn't find that
operation in the standard. Is there any workaround or other packages to
do this?

You can do it the same way you would on an unsigned integral type (which
shifts):

#include <bitset>
#include <string>
#include <iostream>

template <std::size_t N>
inline
void
rotate(std::bitset<N>& b, unsigned m)
{
b = b << m | b >> (N-m);
}

int main()
{
std::bitset<20> b(std::string("00001111111111111111"));
std::cout << b << '\n';
rotate(b, 4);
std::cout << b << '\n';
}