Logo AND Algorithmique Numérique Distribuée

Public GIT Repository
Add new entry in Release_Notes.
[simgrid.git] / include / xbt / utility.hpp
index c39cf85..c35be72 100644 (file)
@@ -1,4 +1,4 @@
-/* Copyright (c) 2016-2020. The SimGrid Team.
+/* Copyright (c) 2016-2023. The SimGrid Team.
  * All rights reserved.                                                     */
 
 /* This program is free software; you can redistribute it and/or modify it
@@ -7,11 +7,43 @@
 #ifndef XBT_UTILITY_HPP
 #define XBT_UTILITY_HPP
 
-#include <tuple>
+#include <array>
 #include <functional>
+#include <tuple>
+#include <type_traits>
+#include <xbt/base.h>
+
+/** @brief Helper macro to declare enum class
+ *
+ * Declares an enum class EnumType, and a function "const char* to_c_str(EnumType)" to retrieve a C-string description
+ * for each value.
+ */
+#define XBT_DECLARE_ENUM_CLASS(EnumType, ...)                                                                          \
+  enum class EnumType;                                                                                                 \
+  static constexpr char const* to_c_str(EnumType value)                                                                \
+  {                                                                                                                    \
+    constexpr std::array<const char*, _XBT_COUNT_ARGS(__VA_ARGS__)> names{{_XBT_STRINGIFY_ARGS(__VA_ARGS__)}};         \
+    return names.at(static_cast<int>(value));                                                                          \
+  }                                                                                                                    \
+  static constexpr bool is_valid_##EnumType(int raw_value)                                                             \
+  {                                                                                                                    \
+    return raw_value >= 0 && raw_value < _XBT_COUNT_ARGS(__VA_ARGS__);                                                 \
+  }                                                                                                                    \
+  enum class EnumType { __VA_ARGS__ } /* defined here to handle trailing semicolon */
+
+namespace simgrid::xbt {
+
+/** @brief Replacement for C++20's std::type_identity_t
+ */
+#if __cplusplus >= 201806L // __cpp_lib_type_identity
+template <class T> using type_identity_t = typename std::type_identity_t<T>;
+#else
+template <class T> struct type_identity {
+  using type = T;
+};
 
-namespace simgrid {
-namespace xbt {
+template <class T> using type_identity_t = typename type_identity<T>::type;
+#endif
 
 /** @brief A hash which works with more stuff
  *
@@ -47,69 +79,5 @@ template <class List, class Elem> inline void intrusive_erase(List& list, Elem&
   list.erase(list.iterator_to(elem));
 }
 
-// integer_sequence and friends from C++14
-// We need them to implement `apply` from C++17.
-
-/** A compile-time sequence of integers (from C++14)
- *
- * `index_sequence<std::size_t,1,5,7,9>` represents the sequence `(1,5,7,9)`.
- *
- * @code{.cpp}
- * template<class T, std::size_t... I>
- * auto extract_tuple(T&& t, integer_sequence<std::size_t, I...>)
- *   -> decltype(std::make_tuple(std::get<I>(std::forward<T>(t))...))
- * {
- *  return std::make_tuple(std::get<I>(std::forward<T>(t))...);
- * }
- *
- * int main()
- * {
- *   integer_sequence<std::size_t, 1, 3> seq;
- *   auto a = std::make_tuple(1, 2.0, false, 'a');
- *   auto b = extract_tuple(a, seq);
- *   std::cout << std::get<0>(b) << '\n'; // 2
- *   std::cout << std::get<1>(b) << '\n'; // a
- *   return 0;
- * }
- * @endcode
- */
-template<class T, T... N>
-class integer_sequence {
-};
-
-namespace bits {
-  template<class T, long long N, long long... M>
-  struct make_integer_sequence :
-    make_integer_sequence<T, N-1, N-1, M...>
-  {};
-  template<class T, long long... M>
-  struct make_integer_sequence<T, 0, M...> {
-    typedef integer_sequence<T, (T) M...> type;
-  };
-}
-
-/** A compile-time sequence of integers of the form `(0,1,2,3,...,N-1)` (from C++14) */
-template<class T, T N>
-using make_integer_sequence = typename simgrid::xbt::bits::make_integer_sequence<T,N>::type;
-
-/** A compile-time sequence of indices (from C++14) */
-template<std::size_t... Ints>
-using index_sequence = integer_sequence<std::size_t, Ints...>;
-
-/** A compile-time sequence of indices of the form `(0,1,2,3,...,N-1)` (from C++14) */
-template<std::size_t N>
-using make_index_sequence = make_integer_sequence<std::size_t, N>;
-
-/** Convert a type parameter pack into a index_sequence (from C++14) */
-template<class... T>
-using index_sequence_for = make_index_sequence<sizeof...(T)>;
-
-static_assert(std::is_same< make_index_sequence<0>, index_sequence<> >::value, "seq0");
-static_assert(std::is_same< make_index_sequence<1>, index_sequence<0> >::value, "seq1");
-static_assert(std::is_same< make_index_sequence<2>, index_sequence<0, 1> >::value, "seq2");
-static_assert(std::is_same< make_index_sequence<3>, index_sequence<0, 1, 2> >::value, "seq3");
-static_assert(std::is_same< index_sequence_for<int,double,float>, make_index_sequence<3> >::value, "seq4");
-
-}
-}
+} // namespace simgrid::xbt
 #endif