From 7c91e1cc5be01dcbd06e0806781a9c15480a4a91 Mon Sep 17 00:00:00 2001
From: q66 <daniel@octaforge.org>
Date: Sat, 23 May 2015 18:55:22 +0100
Subject: [PATCH] implement random access requirements on MapRange

---
 octa/algorithm.h | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/octa/algorithm.h b/octa/algorithm.h
index a2b5b96..f85c66a 100644
--- a/octa/algorithm.h
+++ b/octa/algorithm.h
@@ -388,7 +388,7 @@ namespace octa {
 
     template<typename T>
     struct MapRange: InputRange<
-        MapRange<T>, InputRangeTag, RangeValue<T>, RangeValue<T>, RangeSize<T>
+        MapRange<T>, RangeCategory<T>, RangeValue<T>, RangeValue<T>, RangeSize<T>
     > {
     private:
         T p_range;
@@ -413,10 +413,22 @@ namespace octa {
         }
 
         bool empty() const { return p_range.empty(); }
+        RangeSize<T> length() const { return p_range.length(); }
+
         void pop_first() { p_range.pop_first(); }
+        void pop_last() { p_range.pop_last(); }
+
         RangeSize<T> pop_first_n(RangeSize<T> n) { p_range.pop_first_n(n); }
+        RangeSize<T> pop_last_n(RangeSize<T> n) { p_range.pop_last_n(n); }
 
         RangeValue<T> first() { return p_func(p_range.first()); }
+        RangeValue<T> last() { return p_func(p_range.last()); }
+
+        RangeValue<T> operator[](RangeSize<T> idx) { return p_func(p_range[idx]); }
+
+        MapRange<T> slice(RangeSize<T> start, RangeSize<T> end) {
+            return MapRange<T>(p_range.slice(start, end), p_func);
+        }
 
         bool operator==(const MapRange &v) const {
             return (p_range == v.p_range) && (p_func == v.p_func);