Fix for #313

Author: Iskaban10

source/mir/ndslice/slice.d

@@ -299,6 +299,54 @@ auto sliced(size_t N, Iterator)(return scope Iterator iterator, size_t[N] length
     assert(slice[1, 2] == 12);
 }
 
+/++
+Creates an n-dimensional slice-shell over an iterator having the exact elemnt count as that of the array.
+Params:
+    iterator = An iterator, a pointer, or an array.
+    lengths = A list of lengths for each dimension
+Returns:
+    n-dimensional slice
++/
+auto slicedExactly(size_t N, Iterator)(return scope Iterator iterator, size_t[N] lengths...)
+    if (!__traits(isStaticArray, Iterator) && N
+        && !is(Iterator : Slice!(_Iterator, _N, kind), _Iterator, size_t _N, SliceKind kind))
+{
+    alias C = ImplicitlyUnqual!(typeof(iterator));
+    size_t[N] _lengths;
+    foreach (i; Iota!N)
+        _lengths[i] = lengths[i];
+    ptrdiff_t[1] _strides = 0;
+    static if (isDynamicArray!Iterator)
+    {
+        assert(lengthsProduct(_lengths) == iterator.length,
+            "array length should be exactly equal to the product of constructed ndslice lengths");
+        auto ptr = iterator.length ? &iterator[0] : null;
+        return Slice!(typeof(C.init[0])*, N)(_lengths, ptr);
+    }
+    else
+    {
+        // break safety
+        if (false)
+        {
+            ++iterator;
+            --iterator;
+            iterator += 34;
+            iterator -= 34;
+        }
+        import core.lifetime: move;
+        return Slice!(C, N)(_lengths, iterator.move);
+    }
+}
+
+/// Test case for Issue 313 https://github.com/libmir/mir-algorithm/issues/313
+@safe pure nothrow @nogc unittest
+{
+    int[6] values= [1, 2, 3, 4, 5, 6];
+    auto arr = values[];
+    auto s = arr.slicedExactly(2, 3);
+    assert(s.elementCount == arr.length);
+}
+
 /++
 Creates an 1-dimensional slice-shell over an array.
 Params: