\@array[@slice] assignment

plus changes to the aelem tests to check rhs context.

I did \local @A[@s] at the same time, since I was practically copying
and pasting code from aslice (ok, not quite).

op.c

@@ -2649,6 +2649,11 @@ Perl_op_lvalue_flags(pTHX_ OP *o, I32 type, U32 flags)
 	    kid->op_private |= OPpLVREF_ELEM;
 	    kid->op_flags   |= OPf_STACKED;
 	    break;
+	  case OP_ASLICE:
+	    kid->op_type = OP_LVREFSLICE;
+	    kid->op_ppaddr = PL_ppaddr[OP_LVREFSLICE];
+	    kid->op_private &= OPpLVAL_INTRO|OPpLVREF_ELEM;
+	    continue;
 	  default:
 	   badref:
 	    /* diag_listed_as: Can't modify %s in %s */

pp.c

@@ -6223,7 +6223,52 @@ PP(pp_lvref)
 
 PP(pp_lvrefslice)
 {
-    DIE(aTHX_ "Unimplemented");
+    dSP; dMARK; dORIGMARK;
+    AV * const av = (AV *)POPs;
+    const bool localizing = PL_op->op_private & OPpLVAL_INTRO;
+    bool can_preserve = FALSE;
+
+    if (localizing) {
+	MAGIC *mg;
+	HV *stash;
+	SV **svp;
+
+	can_preserve = SvCANEXISTDELETE(av);
+
+	if (SvTYPE(av) == SVt_PVAV) {
+	    SSize_t max = -1;
+
+	    for (svp = MARK + 1; svp <= SP; svp++) {
+		const SSize_t elem = SvIV(*svp);
+		if (elem > max)
+		    max = elem;
+	    }
+	    if (max > AvMAX(av))
+		av_extend(av, max);
+	}
+    }
+
+    while (++MARK <= SP) {
+	SV * const elemsv = *MARK;
+	const SSize_t elem = SvIV(elemsv);
+	bool existent = TRUE;
+
+	if (localizing && can_preserve)
+	    existent = av_exists(av, elem);
+
+	if (localizing && existent) {
+	    SV ** const svp = av_fetch(av, elem, 1);
+	    if (!svp || !*svp)
+		DIE(aTHX_ PL_no_aelem, elem);
+	    save_aelem(av, elem, svp);
+	}
+	else
+	    SAVEADELETE(av, elem);
+
+	*MARK = sv_2mortal(newSV_type(SVt_PVMG));
+	sv_magic(*MARK,(SV *)av,PERL_MAGIC_lvref,(char *)elemsv,HEf_SVKEY);
+    }
+    RETURN;
 }
 
 /*

t/op/lvref.t

@@ -4,7 +4,7 @@ BEGIN {
     set_up_inc("../lib");
 }
 
-plan 48;
+plan 52;
 
 sub on { $::TODO = ' ' }
 sub off{ $::TODO = ''  }
@@ -76,17 +76,32 @@ is *foo{SCALAR}, *bar{GLOB}, 'globref-to-scalarref assignment';
 
 # Array Elements
 
-\$a[0] = \$_;
+sub expect_scalar_cx { wantarray ? 0 : \$_ }
+sub expect_list_cx { wantarray ? (\$_,\$_) : 0 }
+\$a[0] = expect_scalar_cx;
 is \$a[0], \$_, '\$array[0]';
-\($a[1]) = \$_;
+\($a[1]) = expect_list_cx;
 is \$a[1], \$_, '\($array[0])';
 {
   my @a;
-  \$a[0] = \$_;
+  \$a[0] = expect_scalar_cx;
   is \$a[0], \$_, '\$lexical_array[0]';
-  \($a[1]) = \$_;
+  \($a[1]) = expect_list_cx;
   is \$a[1], \$_, '\($lexical_array[0])';
 }
+{
+  my @a;
+  \@a[0,1] = expect_list_cx;
+  is \$a[0].\$a[1], \$_.\$_, '\@array[indices]';
+  \(@a[2,3]) = expect_list_cx;
+  is \$a[0].\$a[1], \$_.\$_, '\(@array[indices])';
+  my $tmp;
+  {
+    \local @a[0,1] = (\$tmp)x2;
+    is \$a[0].\$a[1], \$tmp.\$tmp, '\local @a[indices]';
+  }
+  is \$a[0].\$a[1], \$_.\$_, '\local @a[indices] unwound';
+}
 
 # Hash Elements