merge changes from the defunct ubot

ext/crlib/cr-twin.h

@@ -0,0 +1,64 @@
+//
+// CRLib - Simple library for STL replacement in private projects.
+// Copyright © 2020 YaPB Development Team <team@yapb.ru>.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+// 
+
+#pragma once
+
+#include <crlib/cr-basic.h>
+#include <crlib/cr-movable.h>
+
+CR_NAMESPACE_BEGIN
+
+// simple pair (twin)
+template <typename A, typename B> class Twin final {
+public:
+   A first;
+   B second;
+
+public:
+   template <typename T, typename U> Twin (T &&a, U &&b) : first (cr::forward <T> (a)), second (cr::forward <U> (b)) { }
+   template <typename T, typename U> Twin (const Twin <T, U> &rhs) : first (rhs.first), second (rhs.second) { }
+   template <typename T, typename U> Twin (Twin <T, U> &&rhs) noexcept : first (cr::move (rhs.first)), second (cr::move (rhs.second)) { }
+
+public:
+   explicit Twin () = default;
+   ~Twin () = default;
+
+public:
+   template <typename T, typename U> Twin &operator = (const Twin <T, U> &rhs) {
+      first = rhs.first;
+      second = rhs.second;
+
+      return *this;
+   }
+
+   template <typename T, typename U> Twin &operator = (Twin <T, U> &&rhs) {
+      first = cr::move (rhs.first);
+      second = cr::move (rhs.second);
+
+      return *this;
+   }
+
+   // specialized operators for binary heap, do not use as it's test only second element
+public:
+   friend bool operator < (const Twin &a, const Twin &b) {
+      return a.second < b.second;
+   }
+
+   friend bool operator > (const Twin &a, const Twin &b) {
+      return b.second < a.second;
+   }
+};
+
+CR_NAMESPACE_END