#include <functional>
#include <future>
#include <utility>
+#include <tuple>
#include <xbt/sysdep.h>
+#include <xbt/utility.hpp>
namespace simgrid {
namespace xbt {
return wrapMain(std::move(code), args(argc, argv));
}
+namespace bits {
+template <class F, class Tuple, std::size_t... I>
+constexpr auto apply(F&& f, Tuple&& t, simgrid::xbt::index_sequence<I...>)
+ -> decltype(std::forward<F>(f)(std::get<I>(std::forward<Tuple>(t))...))
+{
+ return std::forward<F>(f)(std::get<I>(std::forward<Tuple>(t))...);
+}
+}
+
+/** Call a functional object with the values in the given tuple (from C++17)
+ *
+ * @code{.cpp}
+ * int foo(int a, bool b);
+ *
+ * auto args = std::make_tuple(1, false);
+ * int res = apply(foo, args);
+ * @encode
+ **/
+template <class F, class Tuple>
+constexpr auto apply(F&& f, Tuple&& t)
+ -> decltype(simgrid::xbt::bits::apply(
+ std::forward<F>(f),
+ std::forward<Tuple>(t),
+ simgrid::xbt::make_index_sequence<
+ std::tuple_size<typename std::decay<Tuple>::type>::value
+ >()))
+{
+ return simgrid::xbt::bits::apply(
+ std::forward<F>(f),
+ std::forward<Tuple>(t),
+ simgrid::xbt::make_index_sequence<
+ std::tuple_size<typename std::decay<Tuple>::type>::value
+ >());
+}
+
+template<class T> class Task;
+
+/** Type-erased run-once task
+ *
+ * * Like std::function but callable only once.
+ * However, it works with move-only types.
+ *
+ * * Like std::packaged_task<> but without the shared state.
+ */
+template<class R, class... Args>
+class Task<R(Args...)> {
+private:
+ // Type-erasure for the code:
+ class Base {
+ public:
+ virtual ~Base() {}
+ virtual R operator()(Args...) = 0;
+ };
+ template<class F>
+ class Impl : public Base {
+ public:
+ Impl(F&& code) : code_(std::move(code)) {}
+ Impl(F const& code) : code_(code) {}
+ ~Impl() override {}
+ R operator()(Args... args) override
+ {
+ return code_(std::forward<Args>(args)...);
+ }
+ private:
+ F code_;
+ };
+ std::unique_ptr<Base> code_;
+public:
+ Task() {}
+ Task(std::nullptr_t) {}
+
+ template<class F>
+ Task(F&& code) :
+ code_(new Impl<F>(std::forward<F>(code))) {}
+
+ operator bool() const { return code_ != nullptr; }
+ bool operator!() const { return code_ == nullptr; }
+
+ template<class... OtherArgs>
+ R operator()(OtherArgs&&... args)
+ {
+ std::unique_ptr<Base> code = std::move(code_);
+ return (*code)(std::forward<OtherArgs>(args)...);
+ }
+};
+
+template<class F, class... Args>
+class TaskImpl {
+private:
+ F code_;
+ std::tuple<Args...> args_;
+ typedef decltype(simgrid::xbt::apply(std::move(code_), std::move(args_))) result_type;
+public:
+ TaskImpl(F code, std::tuple<Args...> args) :
+ code_(std::move(code)),
+ args_(std::move(args))
+ {}
+ result_type operator()()
+ {
+ return simgrid::xbt::apply(std::move(code_), std::move(args_));
+ }
+};
+
+template<class F, class... Args>
+auto makeTask(F code, Args... args)
+-> Task< decltype(code(std::move(args)...))() >
+{
+ TaskImpl<F, Args...> task(std::move(code), std::make_tuple(std::move(args)...));
+ return std::move(task);
+}
+
}
}
