traits::enable_if, algorithm::iota

octa/algorithm.h

@@ -355,6 +355,12 @@ namespace octa {
         }
         return range2;
     }
+
+    template<typename R, typename T>
+    void iota(R range, T value) {
+        for (; !range.empty(); range.pop_first())
+            range.first() = value++;
+    }
 }
 
 #endif

octa/traits.h

@@ -231,6 +231,12 @@ namespace octa {
 
     /* cppreference.com used for reference */
     template<typename T> struct ResultOf: internal::ResultOf<T> {};
+
+    /* enable_if */
+
+    template<bool B, typename T = void> struct enable_if {};
+
+    template<typename T> struct enable_if<true, T> { typedef T type; };
 }
 
 #endif