From 3a3c9967ac079bf15ac0cea7ff52c040c9764392 Mon Sep 17 00:00:00 2001
From: Vegard Storheil Eriksen <zyp@jvnv.net>
Date: Sat, 27 Nov 2010 07:21:21 +0100
Subject: Added CyclicInt convenience class.

---
 common/cyclicint.h | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)
 create mode 100644 common/cyclicint.h

diff --git a/common/cyclicint.h b/common/cyclicint.h
new file mode 100644
index 0000000..3b24399
--- /dev/null
+++ b/common/cyclicint.h
@@ -0,0 +1,80 @@
+#ifndef CYCLICINT_H
+#define CYCLICINT_H
+
+//! Class containing an integer which ranges from 0..N-1.
+//! 
+//! Exceeding the ends will overflow to the other end. Implicit cast to/from int is provided.
+template<int N>
+class CyclicInt {
+	private:
+		int value;
+		
+		CyclicInt set(int v) {
+			value = v < N ? v < 0 ? N - -v % N : v : v % N;
+			return *this;
+		}
+	
+	public:
+		CyclicInt() {
+			
+		}
+		
+		CyclicInt(int v) {
+			set(v);
+		}
+		
+		CyclicInt operator=(int v) {
+			return set(v);
+		}
+		
+		CyclicInt operator+(CyclicInt v) {
+			return value + v.value;
+		}
+		
+		CyclicInt operator+(int v) {
+			return value + v;
+		}
+		
+		CyclicInt operator+=(CyclicInt v) {
+			return set(value + v.value);
+		}
+		
+		CyclicInt operator++() {
+			return set(value + 1);
+		}
+		
+		CyclicInt operator++(int) {
+			int v = value;
+			set(value + 1);
+			return v;
+		}
+		
+		CyclicInt operator-(CyclicInt v) {
+			return value - v.value;
+		}
+		
+		CyclicInt operator-(int v) {
+			return value - v;
+		}
+		
+		CyclicInt operator-=(CyclicInt v) {
+			return set(value - v.value);
+		}
+		
+		CyclicInt operator--() {
+			return set(value - 1);
+		}
+		
+		CyclicInt operator--(int) {
+			int v = value;
+			set(value - 1);
+			return v;
+		}
+		
+		operator int() {
+			return value;
+		}
+};
+
+
+#endif
-- 
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