add series constructor from associative arrays

Author: 9il

source/mir/functional.d

@@ -144,11 +144,16 @@ Unref!(RefTuple!T) unref(V : RefTuple!T, T...)(V value)
 }
 
 /// ditto
-V unref(V)(V value)
+ref V unref(V)(return ref V value)
 {
     return value;
 }
 
+/// ditto
+V unref(V)(V value)
+{
+    return value;
+}
 
 private string joinStrings()(string[] strs)
 {

source/mir/ndslice/allocation.d

@@ -271,9 +271,17 @@ Returns:
 ContiguousSlice!(N, T)
 makeUninitSlice(T, Allocator, size_t N)(auto ref Allocator alloc, size_t[N] lengths...)
 {
-    immutable len = lengthsProduct(lengths);
-    auto array = cast(T[]) alloc.allocate(len * T.sizeof);
-    return array.sliced(lengths);
+    if (immutable len = lengthsProduct(lengths))
+    {
+        auto mem = alloc.allocate(len * T.sizeof);
+        if (mem.length == 0) assert(0);
+        auto array = () @trusted { return cast(T[]) mem; }();
+        return array.sliced(lengths);
+    }
+    else
+    {
+        return T[].init.sliced(lengths);
+    }
 }
 
 ///

source/mir/ndslice/sorting.d

@@ -169,14 +169,15 @@ template sort(alias less = "a < b")
     static if (__traits(isSame, naryFun!less, less))
     ///
     @optmath Slice!(kind, packs, Iterator) sort(SliceKind kind, size_t[] packs, Iterator)
-        (Slice!(kind, packs, Iterator) slice)
+        (Slice!(kind, packs, Iterator) slice) @safe
         if (packs.length == 1)
     {
         if (false) // break safety
         {
             import mir.utility : swapStars;
-            swapStars(slice._iterator, slice._iterator);
-            auto l = less(*slice._iterator, *slice._iterator);
+            auto elem = typeof(*slice._iterator).init;
+            elem = elem;
+            auto l = less(elem, elem);
         }
         import mir.ndslice.topology: flattened;
         if (slice.anyEmpty)