best way to set a bitset with boolean values

Question

Suppose I have 3 bool type values

bool canwalk=true;
bool cantalk=false;
bool caneat=false;

I would like to set a bitset denoting the three

std::bitset<3> foo;

How can I construct a bitset using the boolean values? I want to do something like this

 std::bitset<3> foo(canWalk,cantalk,caneat); //giving me 100

Answer 1

Following the example of Shivendra Agarwal, but using the constructor that receive an unsigned long long, I propose the following variadic template function (to be more generic)

template <typename ... Args>
unsigned long long getULL (Args ... as)
 {
   using unused = int[];

   unsigned long long ret { 0ULL };

   (void) unused { 0, (ret <<= 1, ret |= (as ? 1ULL : 0ULL), 0)... };

   return ret;
 }

that permit the initialization of foo as follows

std::bitset<3> foo{ getULL(canwalk, cantalk, caneat) };

This works only if the dimension of the std::bitset isn't grater of the number of bits in an unsigned long long (with 3 whe are surely safe).

The following is a full working example

#include <bitset>
#include <iostream>

template <typename ... Args>
unsigned long long getULL (Args ... as)
 {
   using unused = int[];

   unsigned long long ret { 0ULL };

   (void) unused { 0, (ret <<= 1, ret |= (as ? 1ULL : 0ULL), 0)... };

   return ret;
 }

int main()
 {
   bool canwalk=true;
   bool cantalk=false;
   bool caneat=false;

   std::bitset<3> foo{ getULL(canwalk, cantalk, caneat) };

   std::cout << foo << std::endl;
 }