libcruft-util/test/hash/tuple.cpp

#include <cruft/util/hash/tuple.hpp>

#include <cruft/util/tap.hpp>

#include <string_view>


// A "hash" that returns the argument's size.
struct size_hash {
    template <typename ValueT>
    std::size_t
    operator () (ValueT const &val) const
    { return std::size (val); }
};


// A 'mix' function that just sums the arguments.
struct sum_mix {
    template <typename ...ValueT>
    std::size_t
    operator () (ValueT ...val) const
    {
        return (val + ...);
    }
};


int
main ()
{
    using namespace std::string_view_literals;

    cruft::hash::tuple<size_hash, sum_mix> h;

    cruft::TAP::logger tap;
    tap.expect_eq (
        h (
            std::make_tuple (
                "foo"sv, std::vector<int> (5)
            )
        ),
        8u,
        "size/sum tuple hash"
    );

    return tap.status ();
}