overload_set.cpp

#include <iostream>

// http://coliru.stacked-crooked.com/a/3d07f7711012d021

// https://stackoverflow.com/q/29661253/865719
// https://connect.microsoft.com/VisualStudio/feedback/details/990223/overloaded-lambda-pattern-fails-to-compile

template <typename L, typename... Ls>
struct overload_set : L, overload_set<Ls...>
{
    using L::operator();
    using overload_set<Ls...>::operator();
    explicit overload_set(L l, Ls... ls) : L(l), overload_set<Ls...>(ls...) {}
};

template <typename L>
struct overload_set<L> : L
{
    using L::operator();
    explicit overload_set(L l) : L(l) {}
};

template <typename... Ls>
overload_set<Ls...> make_overload(Ls... ls)
{
    return overload_set<Ls...>(ls...);
}

int main()
{
    using std::cout;
    using std::endl;

    auto os = make_overload(
        [](int)    { cout << __PRETTY_FUNCTION__ << endl; },
        [](double) { cout << __PRETTY_FUNCTION__ << endl; },
        [](auto)   { cout << __PRETTY_FUNCTION__ << endl; }
    );
    os(1);
    os(1.9);
    os('x');
}