X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/b66c18380daff78efdc5edf3f6b563b34f36bdfc..e71a2a302d28430dc1bfee906f842f5f3d0fa3ce:/include/xbt/functional.hpp

diff --git a/include/xbt/functional.hpp b/include/xbt/functional.hpp
index 5f530ea928..4f5ca2ce32 100644
--- a/include/xbt/functional.hpp
+++ b/include/xbt/functional.hpp
@@ -1,5 +1,4 @@
-/* Copyright (c) 2015-2016. The SimGrid Team.
- * All rights reserved.                                                     */
+/* Copyright (c) 2015-2021. 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. */
@@ -7,10 +6,13 @@
 #ifndef XBT_FUNCTIONAL_HPP
 #define XBT_FUNCTIONAL_HPP
 
+#include <xbt/sysdep.h>
+
 #include <cstddef>
 #include <cstdlib>
 #include <cstring>
 
+#include <algorithm>
 #include <array>
 #include <exception>
 #include <functional>
@@ -21,42 +23,34 @@
 #include <utility>
 #include <vector>
 
-#include <xbt/sysdep.h>
-#include <xbt/utility.hpp>
-
 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_;
-    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;
-    code_(argc, argv.get());
+    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
-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()> wrapMain(F code, int argc, const char*const argv[])
+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);
   return MainFunction<F>(std::move(code), std::move(args));
@@ -64,8 +58,8 @@ 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))...))
+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))...);
 }
@@ -78,23 +72,15 @@ constexpr auto apply(F&& f, Tuple&& t, simgrid::xbt::index_sequence<I...>)
  *
  *  auto args = std::make_tuple(1, false);
  *  int res = apply(foo, args);
- *  @encode
+ *  @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_t<Tuple>>::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
-    >());
+  return simgrid::xbt::bits::apply(std::forward<F>(f), std::forward<Tuple>(t),
+                                   std::make_index_sequence<std::tuple_size<typename std::decay_t<Tuple>>::value>());
 }
 
 template<class T> class Task;
@@ -108,29 +94,12 @@ 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() {}
-    ~TaskUnion() {}
-  };
-#endif
+  using TaskUnion =
+      typename std::aligned_union_t<0, void*, std::pair<void (*)(), void*>, std::pair<void (whatever::*)(), whatever*>>;
 
   // Is F suitable for small buffer optimization?
   template<class F>
@@ -144,11 +113,11 @@ 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 {
@@ -167,9 +136,8 @@ private:
   }
 
 public:
-
-  Task() {}
-  Task(std::nullptr_t) {}
+  Task() = default;
+  explicit Task(std::nullptr_t) { /* Nothing to do */}
   ~Task()
   {
     this->clear();
@@ -177,52 +145,51 @@ 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(&buffer_, &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(&buffer_, &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)
+  template <class F> typename std::enable_if_t<canSBO<F>()> init(F code)
   {
     const static TaskVtable vtable {
       // Call:
-      [](TaskUnion& buffer, Args... args) -> R {
-        F* src = reinterpret_cast<F*>(&buffer);
+      [](TaskUnion& buffer, Args... args) {
+        auto* src = reinterpret_cast<F*>(&buffer);
         F code = std::move(*src);
         src->~F();
-        code(std::forward<Args>(args)...);
+        // 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();
       }
@@ -231,15 +198,14 @@ private:
     vtable_ = &vtable;
   }
 
-  template<class F>
-  typename std::enable_if<!canSBO<F>()>::type
-  init(F code)
+  template <class F> typename std::enable_if_t<not canSBO<F>()> init(F code)
   {
     const static TaskVtable vtable {
       // Call:
-      [](TaskUnion& buffer, Args... args) -> R {
+      [](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:
@@ -255,12 +221,7 @@ private:
   }
 
 public:
-
-  template<class F>
-  Task(F code)
-  {
-    this->init(std::move(code));
-  }
+  template <class F> explicit Task(F code) { this->init(std::move(code)); }
 
   operator bool() const { return vtable_ != nullptr; }
   bool operator!() const { return vtable_ == nullptr; }
@@ -271,16 +232,18 @@ 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)),
@@ -292,15 +255,12 @@ public:
   }
 };
 
-template<class F, class... Args>
-auto makeTask(F code, Args... args)
--> Task< decltype(code(std::move(args)...))() >
+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 std::move(task);
-}
-
-}
+  return Task<decltype(code(std::move(args)...))()>(std::move(task));
 }
 
+} // namespace xbt
+} // namespace simgrid
 #endif