WTF C++14

make_resource.cpp

// Not quite as bad as https://twitter.com/ivansafrin/status/457248037157740544 but still hairy.

#include <memory>
#include <type_traits>
#include <iostream>

template <typename Creator, typename Destructor, typename... Arguments>
auto make_resource(Creator c, Destructor d, Arguments &&... args) {
    using value_t = typename std::decay<decltype(*c(std::forward<Arguments>(args)...))>::type;
    using ptr_t = std::unique_ptr<value_t, void (*)(value_t *)>;
    return ptr_t(c(std::forward<Arguments>(args)...), d);
}

struct res { int i; };

res *make_res(int i) {
    std::cout << "res{" << i << "}" << std::endl;
    return new res{i};
}
void delete_res(res * p) {
    std::cout << "~res{" << p->i << "}" << std::endl;
    delete p;
}

int main() {
    auto f = make_resource(make_res, delete_res, 123);
}