fix sorting for zip ndslices

Author: 9il

source/mir/functional.d

@@ -98,6 +98,14 @@ struct RefTuple(T...)
     mixin _RefTupleMixin!T;
 }
 
+/// Removes $(LREF Ref) shell.
+alias Unref(V : Ref!T, T) = T;
+/// ditto
+alias Unref(V : RefTuple!T, T...) = RefTuple!(staticMap!(.Unref, T));
+/// ditto
+alias Unref(V) = V;
+
+
 /++
 Returns: a $(LREF RefTuple) structure.
 +/
@@ -106,6 +114,28 @@ RefTuple!Args tuple(Args...)(auto ref Args args)
     return RefTuple!Args(args);
 }
 
+/// Removes $(LREF Ref) shell.
+T unref(V : Ref!T, T)(V value)
+{
+    return *value.__ptr;
+}
+
+/// ditto
+Unref!(RefTuple!T) unref(V : RefTuple!T, T...)(V value)
+{
+    typeof(return) ret;
+    foreach(i, ref elem; ret.expand)
+        elem = value.expand[i].unref;
+    return ret;
+}
+
+/// ditto
+V unref(V)(V value)
+{
+    return value;
+}
+
+
 private string joinStrings()(string[] strs)
 {
     if (strs.length)

source/mir/ndslice/iterator.d

@@ -410,9 +410,19 @@ struct ZipIterator(Iterators...)
             mixin(op ~ `_iterator;`);
     }
 
-    auto ref opIndex()(ptrdiff_t index)
+    auto opIndex()(ptrdiff_t index)
     { return mixin("RefTuple!(_zip_types!Iterators)(" ~ _zip_index!Iterators ~ ")"); }
 
+    auto opIndexAssign(Types...)(RefTuple!(Types) value, ptrdiff_t index)
+        if (Types.length == Iterators.length)
+    {
+        foreach(i, val; value.expand)
+        {
+            _iterators[i][index] = val;
+        }
+        return opIndex(index);
+    }
+
     void opOpAssign(string op)(ptrdiff_t index)
         if (op == "+" || op == "-")
     {

source/mir/ndslice/sorting.d

@@ -148,7 +148,8 @@ void quickSortImpl(alias less, Iterator)(Slice!(Contiguous, [1], Iterator) slice
                     //    })))
                     //{
                         auto d = p;
-                        auto temp = *d;
+                        import mir.functional: unref;
+                        auto temp = unref(*d);
                         auto c = d;
                         ++c;
                         if (less(*c, temp))
@@ -191,7 +192,8 @@ void quickSortImpl(alias less, Iterator)(Slice!(Contiguous, [1], Iterator) slice
         --r;
         auto pivotIdx = l + slice.length / 2;
         setPivot!less(slice.length, l, pivotIdx, r);
-        auto pivot = *pivotIdx;
+        import mir.functional: unref;
+        auto pivot = unref(*pivotIdx);
         --lessI;
         auto greaterI = r;
         swapStars(pivotIdx, greaterI);

source/mir/utility.d

@@ -30,7 +30,8 @@ void swapStars(I1, I2)(auto ref I1 i1, auto ref I2 i2)
     }
     else
     {
-        auto e = *i1;
+        import mir.functional: unref;
+        auto e = unref(*i1);
         i1[0] = *i2;
         i2[0] = e;
     }