[idd] common: centralize nonzero sequences

idd/LGCommon/Seq.h

@@ -0,0 +1,54 @@
+/**
+ * Looking Glass
+ * Copyright © 2017-2026 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * 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 2 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#pragma once
+
+#include <type_traits>
+
+namespace Seq
+{
+  template<typename T>
+  T Next(T value)
+  {
+    static_assert(std::is_integral<T>::value &&
+      std::is_unsigned<T>::value && !std::is_same<T, bool>::value,
+      "sequence type must be an unsigned integer");
+
+    const T next = value + static_cast<T>(1);
+    return next ? next : static_cast<T>(1);
+  }
+
+  template<typename T>
+  T Inc(T& value)
+  {
+    value = Next(value);
+    return value;
+  }
+
+  template<typename T>
+  T Take(T& value)
+  {
+    if (!value)
+      value = static_cast<T>(1);
+    const T result = value;
+    value = Next(value);
+    return result;
+  }
+}