X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/2618e74f3013e614762462ffb63bbe094fd1ae40..e71a2a302d28430dc1bfee906f842f5f3d0fa3ce:/include/xbt/Extendable.hpp

diff --git a/include/xbt/Extendable.hpp b/include/xbt/Extendable.hpp
index d90314d4c8..6f8e0fc6aa 100644
--- a/include/xbt/Extendable.hpp
+++ b/include/xbt/Extendable.hpp
@@ -1,4 +1,4 @@
-/* Copyright (c) 2015. The SimGrid Team.
+/* Copyright (c) 2015-2021. The SimGrid Team.
  * All rights reserved.                                                     */
 
 /* This program is free software; you can redistribute it and/or modify it
@@ -19,14 +19,14 @@ template<class T>          class Extendable;
 
 template<class T, class U>
 class Extension {
-  static const std::size_t INVALID_ID = std::numeric_limits<std::size_t>::max();
-  std::size_t id_;
+  static constexpr std::size_t INVALID_ID = std::numeric_limits<std::size_t>::max();
+  std::size_t id_                         = INVALID_ID;
   friend class Extendable<T>;
-  constexpr Extension(std::size_t id) : id_(id) {}
+  explicit constexpr Extension(std::size_t id) : id_(id) {}
 public:
-  explicit constexpr Extension() : id_(INVALID_ID) {}
+  explicit constexpr Extension() = default;
   std::size_t id() const { return id_; }
-  bool valid() { return id_ != INVALID_ID; }
+  bool valid() const { return id_ != INVALID_ID; }
 };
 
 /** An Extendable is an object that you can extend with external elements.
@@ -48,14 +48,16 @@ template<class T>
 class Extendable {
 private:
   static std::vector<void(*)(void*)> deleters_;
-protected:
-  std::vector<void*> extensions_;
+  std::vector<void*> extensions_{std::max<decltype(deleters_.size())>(1, deleters_.size()), nullptr};
+
 public:
   static size_t extension_create(void (*deleter)(void*))
   {
-    std::size_t res = deleters_.size();
+    if (deleters_.empty()) { // Save space for void* user data
+      deleters_.push_back(nullptr);
+    }
     deleters_.push_back(deleter);
-    return res;
+    return deleters_.size() - 1;
   }
   template<class U>
   static Extension<T,U> extension_create(void (*deleter)(void*))
@@ -65,9 +67,11 @@ public:
   template<class U> static
   Extension<T,U> extension_create()
   {
-    return extension_create([](void* p){ delete static_cast<U*>(p); });
+    return Extension<T, U>(extension_create([](void* p) { delete static_cast<U*>(p); }));
   }
-  Extendable() : extensions_(deleters_.size(), nullptr) {}
+  Extendable()                  = default;
+  Extendable(const Extendable&) = delete;
+  Extendable& operator=(const Extendable&) = delete;
   ~Extendable()
   {
     /* Call destructors in reverse order of their registrations
@@ -76,49 +80,44 @@ public:
      * an extension A, the subsystem of B might depend on the subsystem on A and
      * an extension of B might need to have the extension of A around when executing
      * its cleanup function/destructor. */
-    for (std::size_t i = extensions_.size(); i > 0; --i)
+    for (std::size_t i = extensions_.size(); i > 1; --i) // rank=0 is the spot of user's void*
       if (extensions_[i - 1] != nullptr && deleters_[i - 1] != nullptr)
         deleters_[i - 1](extensions_[i - 1]);
   }
 
   // Type-unsafe versions of the facet access methods:
-  void* extension(std::size_t rank)
+  void* extension(std::size_t rank) const
   {
-    if (rank >= extensions_.size())
-      return nullptr;
-    else
-      return extensions_.at(rank);
+    return rank < extensions_.size() ? extensions_[rank] : nullptr;
   }
   void extension_set(std::size_t rank, void* value, bool use_dtor = true)
   {
     if (rank >= extensions_.size())
       extensions_.resize(rank + 1, nullptr);
     void* old_value = this->extension(rank);
-    extensions_.at(rank) = value;
+    extensions_[rank] = value;
     if (use_dtor && old_value != nullptr && deleters_[rank])
       deleters_[rank](old_value);
   }
 
   // Type safe versions of the facet access methods:
-  template<class U>
-  U* extension(Extension<T,U> rank)
-  {
-    return static_cast<U*>(extension(rank.id()));
-  }
+  template <class U> U* extension(Extension<T, U> rank) const { return static_cast<U*>(extension(rank.id())); }
   template<class U>
   void extension_set(Extension<T,U> rank, U* value, bool use_dtor = true)
   {
     extension_set(rank.id(), value, use_dtor);
   }
-
-  // Convenience extension access when the type has a associated EXTENSION ID:
-  template<class U> U* extension()           { return extension<U>(U::EXTENSION_ID); }
+  // void* version, for C users and nostalgics
+  void set_data(void* data){
+    extensions_[0]=data;
+  }
+  void* get_data() const { return extensions_[0]; }
+  // Convenience extension access when the type has an associated EXTENSION ID:
+  template <class U> U* extension() const { return extension<U>(U::EXTENSION_ID); }
   template<class U> void extension_set(U* p) { extension_set<U>(U::EXTENSION_ID, p); }
 };
 
-template<class T>
-std::vector<void(*)(void*)> Extendable<T>::deleters_ = {};
-
+template <class T> std::vector<void (*)(void*)> Extendable<T>::deleters_;
 }
 }