X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/f23b0fb864cb60978c1fcfd48d50f62dd054fe31..cff982bd049d26d7acbd0e23324e0de051b06d0d:/include/xbt/functional.hpp

diff --git a/include/xbt/functional.hpp b/include/xbt/functional.hpp
index 4b5f0afc10..b8695631a1 100644
--- a/include/xbt/functional.hpp
+++ b/include/xbt/functional.hpp
@@ -1,4 +1,4 @@
-/* Copyright (c) 2015-2018. The SimGrid Team. All rights reserved.          */
+/* Copyright (c) 2015-2020. The SimGrid Team. All rights reserved.          */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
@@ -7,12 +7,12 @@
 #define XBT_FUNCTIONAL_HPP
 
 #include <xbt/sysdep.h>
-#include <xbt/utility.hpp>
 
 #include <cstddef>
 #include <cstdlib>
 #include <cstring>
 
+#include <algorithm>
 #include <array>
 #include <exception>
 #include <functional>
@@ -26,51 +26,30 @@
 namespace simgrid {
 namespace xbt {
 
-template<class F>
-class MainFunction {
-private:
+template <class F> class MainFunction {
   F code_;
   std::shared_ptr<const std::vector<std::string>> args_;
+
 public:
-  MainFunction(F code, std::vector<std::string> args) :
-    code_(std::move(code)),
-    args_(std::make_shared<const std::vector<std::string>>(std::move(args)))
-  {}
+  MainFunction(F code, std::vector<std::string>&& args)
+      : code_(std::move(code)), args_(std::make_shared<const std::vector<std::string>>(std::move(args)))
+  {
+  }
   void operator()() const
   {
-    const int argc = args_->size();
+    const int argc                = args_->size();
     std::vector<std::string> args = *args_;
-    if (not args.empty()) {
-      char noarg[] = {'\0'};
-      std::unique_ptr<char* []> argv(new char*[argc + 1]);
-      for (int i = 0; i != argc; ++i)
-        argv[i]  = args[i].empty() ? noarg : &args[i].front();
-      argv[argc] = nullptr;
-      code_(argc, argv.get());
-    } else
-      code_(argc, nullptr);
+    std::vector<char*> argv(args.size() + 1); // argv[argc] is nullptr
+    std::transform(begin(args), end(args), begin(argv), [](std::string& s) { return &s.front(); });
+    code_(argc, argv.data());
   }
 };
 
-template <class F>
-inline XBT_ATTRIB_DEPRECATED_v323("Please use wrap_main()") std::function<void()> wrapMain(
-    F code, std::vector<std::string> args)
+template <class F> inline std::function<void()> wrap_main(F code, std::vector<std::string>&& args)
 {
   return MainFunction<F>(std::move(code), std::move(args));
 }
 
-template <class F> inline std::function<void()> wrap_main(F code, std::vector<std::string> args)
-{
-  return MainFunction<F>(std::move(code), std::move(args));
-}
-
-template <class F>
-inline XBT_ATTRIB_DEPRECATED_v323("Please use wrap_main()") std::function<void()> wrapMain(F code, int argc,
-                                                                                           const char* const argv[])
-{
-  std::vector<std::string> args(argv, argv + argc);
-  return MainFunction<F>(std::move(code), std::move(args));
-}
 template <class F> inline std::function<void()> wrap_main(F code, int argc, const char* const argv[])
 {
   std::vector<std::string> args(argv, argv + argc);
@@ -79,8 +58,8 @@ template <class F> inline std::function<void()> wrap_main(F code, int argc, cons
 
 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))...))
+constexpr auto apply(F&& f, Tuple&& t, std::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))...);
 }
@@ -96,20 +75,13 @@ constexpr auto apply(F&& f, Tuple&& t, simgrid::xbt::index_sequence<I...>)
  *  @endcode
  **/
 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
-    >()))
+constexpr auto apply(F&& f, Tuple&& t) -> decltype(
+    simgrid::xbt::bits::apply(std::forward<F>(f), std::forward<Tuple>(t),
+                              std::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
-    >());
+      std::forward<F>(f), std::forward<Tuple>(t),
+      std::make_index_sequence<std::tuple_size<typename std::decay<Tuple>::type>::value>());
 }
 
 template<class T> class Task;
@@ -123,29 +95,12 @@ template<class T> class Task;
  */
 template<class R, class... Args>
 class Task<R(Args...)> {
-private:
-
   // Placeholder for some class type:
   struct whatever {};
 
   // Union used for storage:
-#if 0
-  typedef typename std::aligned_union<0,
-    void*,
-    std::pair<void(*)(),void*>,
-    std::pair<void(whatever::*)(), whatever*>
-  >::type TaskUnion;
-#else
-  union TaskUnion {
-    void* ptr;
-    std::pair<void(*)(),void*> funcptr;
-    std::pair<void(whatever::*)(), whatever*> memberptr;
-    char any1[sizeof(std::pair<void(*)(),void*>)];
-    char any2[sizeof(std::pair<void(whatever::*)(), whatever*>)];
-    TaskUnion() { /* Nothing to do */}
-    ~TaskUnion() { /* Nothing to do */}
-  };
-#endif
+  using TaskUnion = typename std::aligned_union<0, void*, std::pair<void (*)(), void*>,
+                                                std::pair<void (whatever::*)(), whatever*>>::type;
 
   // Is F suitable for small buffer optimization?
   template<class F>
@@ -159,11 +114,11 @@ private:
     "SBO not working for reference_wrapper");
 
   // Call (and possibly destroy) the function:
-  typedef R (*call_function)(TaskUnion&, Args...);
+  using call_function = R (*)(TaskUnion&, Args...);
   // Destroy the function (of needed):
-  typedef void (*destroy_function)(TaskUnion&);
+  using destroy_function = void (*)(TaskUnion&);
   // Move the function (otherwise memcpy):
-  typedef void (*move_function)(TaskUnion& dest, TaskUnion& src);
+  using move_function = void (*)(TaskUnion& dest, TaskUnion& src);
 
   // Vtable of functions for manipulating whatever is in the TaskUnion:
   struct TaskVtable {
@@ -182,7 +137,7 @@ private:
   }
 
 public:
-  Task() { /* Nothing to do */}
+  Task() = default;
   explicit Task(std::nullptr_t) { /* Nothing to do */}
   ~Task()
   {
@@ -191,30 +146,29 @@ public:
 
   Task(Task const&) = delete;
 
-  Task(Task&& that)
+  Task(Task&& that) noexcept
   {
     if (that.vtable_ && that.vtable_->move)
       that.vtable_->move(buffer_, that.buffer_);
     else
       std::memcpy(static_cast<void*>(&buffer_), static_cast<void*>(&that.buffer_), sizeof(buffer_));
-
-    vtable_ = that.vtable_;
+    vtable_      = std::move(that.vtable_);
     that.vtable_ = nullptr;
   }
-  Task& operator=(Task that)
+  Task& operator=(Task const& that) = delete;
+  Task& operator=(Task&& that) noexcept
   {
     this->clear();
     if (that.vtable_ && that.vtable_->move)
       that.vtable_->move(buffer_, that.buffer_);
     else
       std::memcpy(static_cast<void*>(&buffer_), static_cast<void*>(&that.buffer_), sizeof(buffer_));
-    vtable_ = that.vtable_;
+    vtable_      = std::move(that.vtable_);
     that.vtable_ = nullptr;
     return *this;
   }
 
 private:
-
   template<class F>
   typename std::enable_if<canSBO<F>()>::type
   init(F code)
@@ -222,22 +176,23 @@ private:
     const static TaskVtable vtable {
       // Call:
       [](TaskUnion& buffer, Args... args) {
-        F* src = reinterpret_cast<F*>(&buffer);
+        auto* src = reinterpret_cast<F*>(&buffer);
         F code = std::move(*src);
         src->~F();
+        // NOTE: std::forward<Args>(args)... is correct.
         return code(std::forward<Args>(args)...);
       },
       // Destroy:
       std::is_trivially_destructible<F>::value ?
       static_cast<destroy_function>(nullptr) :
       [](TaskUnion& buffer) {
-        F* code = reinterpret_cast<F*>(&buffer);
+        auto* code = reinterpret_cast<F*>(&buffer);
         code->~F();
       },
       // Move:
       [](TaskUnion& dst, TaskUnion& src) {
-        F* src_code = reinterpret_cast<F*>(&src);
-        F* dst_code = reinterpret_cast<F*>(&dst);
+        auto* src_code = reinterpret_cast<F*>(&src);
+        auto* dst_code = reinterpret_cast<F*>(&dst);
         new(dst_code) F(std::move(*src_code));
         src_code->~F();
       }
@@ -253,6 +208,7 @@ private:
       [](TaskUnion& buffer, Args... args) {
         // Delete F when we go out of scope:
         std::unique_ptr<F> code(*reinterpret_cast<F**>(&buffer));
+        // NOTE: std::forward<Args>(args)... is correct.
         return (*code)(std::forward<Args>(args)...);
       },
       // Destroy:
@@ -279,16 +235,18 @@ public:
       throw std::bad_function_call();
     const TaskVtable* vtable = vtable_;
     vtable_ = nullptr;
+    // NOTE: std::forward<Args>(args)... is correct.
+    // see C++ [func.wrap.func.inv] for an example
     return vtable->call(buffer_, std::forward<Args>(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;
+  using result_type = decltype(simgrid::xbt::apply(std::move(code_), std::move(args_)));
+
 public:
   TaskImpl(F code, std::tuple<Args...> args) :
     code_(std::move(code)),
@@ -300,20 +258,12 @@ public:
   }
 };
 
-template <class F, class... Args>
-XBT_ATTRIB_DEPRECATED_v323("Please use make_task()") 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 Task<decltype(code(std::move(args)...))()>(std::move(task));
-}
-
 template <class F, class... Args> auto make_task(F code, Args... args) -> Task<decltype(code(std::move(args)...))()>
 {
   TaskImpl<F, Args...> task(std::move(code), std::make_tuple(std::move(args)...));
   return Task<decltype(code(std::move(args)...))()>(std::move(task));
 }
-}
-}
 
+} // namespace xbt
+} // namespace simgrid
 #endif