[Bug c++/71446] Incorrect overload resolution when using designated initializers

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71446

--- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
So like (untested):
--- gcc/call.c.jj       2019-02-28 08:14:58.251562934 +0100
+++ gcc/call.c  2019-02-28 17:04:49.697357298 +0100
@@ -819,7 +819,7 @@ build_list_conv (tree type, tree ctor, i
   conversion **subconvs = alloc_conversions (len);
   conversion *t;
   unsigned i;
-  tree val;
+  tree val, idx;

   /* Within a list-initialization we can have more user-defined
      conversions.  */
@@ -833,8 +833,12 @@ build_list_conv (tree type, tree ctor, i
       || VOID_TYPE_P (elttype))
     return NULL;

-  FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
+  FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), i, idx, val)
     {
+      /* If there are any designators, ck_list is not valid.  */
+      if (idx != NULL_TREE)
+       return NULL;
+
       conversion *sub
        = implicit_conversion (elttype, TREE_TYPE (val), val,
                               false, flags, complain);
@@ -1030,7 +1034,7 @@ build_complex_conv (tree type, tree ctor
   unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor);
   tree elttype = TREE_TYPE (type);
   unsigned i;
-  tree val;
+  tree idx, val;
   bool bad = false;
   bool user = false;
   enum conversion_rank rank = cr_exact;
@@ -1040,8 +1044,12 @@ build_complex_conv (tree type, tree ctor

   flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING;

-  FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
+  FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), i, idx, val)
     {
+      /* If there are any designators, complex conv is not valid.  */
+      if (idx != NULL_TREE)
+       return NULL;
+
       conversion *sub
        = implicit_conversion (elttype, TREE_TYPE (val), val,
                               false, flags, complain);
@@ -1896,7 +1904,7 @@ implicit_conversion (tree to, tree from,

          if (nelts == 0)
            elt = build_value_init (to, tf_none);
-         else if (nelts == 1)
+         else if (nelts == 1 && CONTRUCTOR_ELT (expr, 0)->index == NULL_TREE)
            elt = CONSTRUCTOR_ELT (expr, 0)->value;
          else
            elt = error_mark_node;