enumerate indices of multidimentional array .cpp

#include <utility>

template< typename F, std::size_t ...indices >
struct enumerator
{
    static constexpr const std::size_t size_ = sizeof...(indices);
    static constexpr const std::size_t count_ = (indices * ...);

    template< typename I >
    struct decomposer;
    
    template< std::size_t ...I >
    struct decomposer< std::index_sequence< I... > >
    {
        F & f;
        
        static constexpr const std::size_t indices_[size_] = {indices...};
        
        static
        constexpr
        std::size_t
        order(std::size_t const i)
        {
            std::size_t o = 1;
            for (std::size_t n = i + 1; n < size_; ++n) {
                o *= indices_[n];
            }
            return o;
        }
        
        static constexpr std::size_t const orders_[size_] = {order(I)...};
        
        static
        constexpr
        std::size_t
        digit(std::size_t c, std::size_t const i)
        {
            for (std::size_t n = 0; n < i; ++n) {
                c = c % orders_[n];
            }
            return c / orders_[i];
        }
        
        template< std::size_t c >
        constexpr
        bool
        call() const
        {
            return f.template operator () < digit(c, I)... >(); // error here
        }
        
    };
    
    decomposer< std::make_index_sequence< size_ > > decomposer_;

    constexpr
    bool
    operator () () const
    {
        return call(std::make_index_sequence< count_ >{});
    }
    
    template< std::size_t ...counter >
    constexpr
    bool
    call(std::index_sequence< counter... >) const
    {
        return (decomposer_.template call< counter >() && ...);
    }
};

#include <iterator>
#include <iostream>
#include <initializer_list>
#include <algorithm>

#include <cstdlib>

struct print
{
    template< std::size_t ...indices >
    constexpr
    bool
    operator () () const
    {
        for (std::size_t const i : {indices...}) {
            std::cout << i << ' ';
        }
        std::cout << std::endl;
        return true;
    }
};

int
main()
{
    print const print_{};
    enumerator< print const, 11, 7, 3 >{{print_}}();
    return EXIT_SUCCESS;
}