Re: [Boost-users] [tuple][hash] Hashing a tuple question

30 Jun 2008

      AMDG

Milosz Marian Hulboj wrote:
...
I'm looking for advice on hashing the tuples. For my task it seems to be enough to just take every element from the tuple and apply boost::hash_combine to each of the elements. However I am currently thinking of a clever way of writing it in a generic form. Has anyone done something like that and could give some hints?
#include <iostream>
#include <cstddef>

#include 
#include 

#include 

struct hash_combine {
    typedef std::size_t result_type;
    template<class T>
    std::size_t operator()(const T& arg, std::size_t current) {
        boost::hash_combine(current, arg);
        return(current);
    }
};

int main() {
    boost::tuple t1(2, 'x', "a string");
    std::size_t hash = boost::fusion::fold(t1, 0, hash_combine());
    std::cout << hash << std::endl;
}

In Christ,
Steven Watanabe