#ifndef XBT_FUNCTIONAL_HPP
#define XBT_FUNCTIONAL_HPP
+#include <cstddef>
#include <cstdlib>
#include <exception>
#include <functional>
-#include <future>
+#include <memory>
+#include <string>
+#include <tuple>
#include <utility>
+#include <vector>
#include <xbt/sysdep.h>
+#include <xbt/utility.hpp>
namespace simgrid {
namespace xbt {
-class args {
+template<class F>
+class MainFunction {
private:
- int argc_ = 0;
- char** argv_ = nullptr;
+ F code_;
+ std::shared_ptr<const std::vector<std::string>> args_;
public:
-
- // Main constructors
- args() {}
-
- void assign(int argc, const char*const* argv)
- {
- clear();
- char** new_argv = xbt_new(char*,argc + 1);
- for (int i = 0; i < argc; i++)
- new_argv[i] = xbt_strdup(argv[i]);
- new_argv[argc] = nullptr;
- this->argc_ = argc;
- this->argv_ = new_argv;
- }
- args(int argc, const char*const* argv)
- {
- this->assign(argc, argv);
- }
-
- char** to_argv() const
+ MainFunction(F code, std::vector<std::string> args) :
+ code_(std::move(code)),
+ args_(std::make_shared<const std::vector<std::string>>(std::move(args)))
+ {}
+ int operator()() const
{
- const int argc = argc_;
- char** argv = xbt_new(char*, argc + 1);
- for (int i=0; i< argc; i++)
- argv[i] = xbt_strdup(argv_[i]);
+ const int argc = args_->size();
+ std::vector<std::string> args = *args_;
+ std::unique_ptr<char*[]> argv(new char*[argc + 1]);
+ for (int i = 0; i != argc; ++i)
+ argv[i] = args[i].empty() ? const_cast<char*>(""): &args[i].front();
argv[argc] = nullptr;
- return argv;
- }
-
- // Free
- void clear()
- {
- for (int i = 0; i < this->argc_; i++)
- std::free(this->argv_[i]);
- std::free(this->argv_);
- this->argc_ = 0;
- this->argv_ = nullptr;
- }
- ~args() { clear(); }
-
- // Copy
- args(args const& that)
- {
- this->assign(that.argc(), that.argv());
- }
- args& operator=(args const& that)
- {
- this->assign(that.argc(), that.argv());
- return *this;
- }
-
- // Move:
- args(args&& that) : argc_(that.argc_), argv_(that.argv_)
- {
- that.argc_ = 0;
- that.argv_ = nullptr;
+ return code_(argc, argv.get());
}
- args& operator=(args&& that)
- {
- this->argc_ = that.argc_;
- this->argv_ = that.argv_;
- that.argc_ = 0;
- that.argv_ = nullptr;
- return *this;
- }
-
- int argc() const { return argc_; }
- char** argv() { return argv_; }
- const char*const* argv() const { return argv_; }
- char* operator[](std::size_t i) { return argv_[i]; }
};
template<class F> inline
-std::function<void()> wrapMain(F code, std::shared_ptr<simgrid::xbt::args> args)
+std::function<void()> wrapMain(F code, std::vector<std::string> args)
{
- return [=]() {
- code(args->argc(), args->argv());
- };
+ return MainFunction<F>(std::move(code), std::move(args));
}
template<class F> inline
-std::function<void()> wrapMain(F code, simgrid::xbt::args args)
+std::function<void()> wrapMain(F code, int argc, const char*const argv[])
{
- return wrapMain(std::move(code),
- std::unique_ptr<simgrid::xbt::args>(new simgrid::xbt::args(std::move(args))));
+ std::vector<std::string> args(argv, argv + argc);
+ return MainFunction<F>(std::move(code), std::move(args));
}
-template<class F> inline
-std::function<void()> wrapMain(F code, int argc, const char*const* 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)...))() >
{
- return wrapMain(std::move(code), args(argc, argv));
+ TaskImpl<F, Args...> task(std::move(code), std::make_tuple(std::move(args)...));
+ return std::move(task);
}
}
