X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/7b138f8b1ed3e8816eda5cb26deb71fe81b4087a..950b9d175a7966b91adf53b74745ce4e6e5da5f9:/include/xbt/utility.hpp

diff --git a/include/xbt/utility.hpp b/include/xbt/utility.hpp
index 09d8db40bf..df3fbf4ccf 100644
--- a/include/xbt/utility.hpp
+++ b/include/xbt/utility.hpp
@@ -1,14 +1,34 @@
-/* Copyright (c) 2016. The SimGrid Team.
+/* Copyright (c) 2016-2018. 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. */
 
+#ifndef XBT_UTILITY_HPP
+#define XBT_UTILITY_HPP
+
 #include <tuple>
 
 namespace simgrid {
 namespace xbt {
 
+/** @brief Comparator class for using with std::priority_queue or boost::heap.
+ *
+ * Compare two std::pair by their first element (of type double), and return true when the first is greater than the
+ * second.  Useful to have priority queues with the smallest element on top.
+ */
+template <class Pair> class HeapComparator {
+public:
+  bool operator()(const Pair& a, const Pair& b) const { return a.first > b.first; }
+};
+
+/** @brief Erase an element given by reference from a boost::intrusive::list.
+ */
+template <class List, class Elem> inline void intrusive_erase(List& list, Elem& elem)
+{
+  list.erase(list.iterator_to(elem));
+}
+
 // integer_sequence and friends from C++14
 // We need them to implement `apply` from C++17.
 
@@ -46,7 +66,7 @@ class integer_sequence {
 namespace bits {
   template<class T, long long N, long long... M>
   struct make_integer_sequence :
-    public make_integer_sequence<T, N-1, N-1, M...>
+    make_integer_sequence<T, N-1, N-1, M...>
   {};
   template<class T, long long... M>
   struct make_integer_sequence<T, 0, M...> {
@@ -78,3 +98,4 @@ static_assert(std::is_same< index_sequence_for<int,double,float>, make_index_seq
 
 }
 }
+#endif