In this testcase, the A conversion template can't possibly produce a
pointer type, so its presence in the overload set shouldn't cause an
error. The standard is unclear about the B case, but it seems
appropriate to me to still complain there.
Tested x86_64-pc-linux-gnu, applying to trunk, 4.8, 4.7.
commit bd43671e5087c4fbee728305af02abd54bafa91e
Author: Jason Merrill <ja...@redhat.com>
Date: Sat Aug 17 21:30:36 2013 -0400
PR c++/58119
* cvt.c (build_expr_type_conversion): Don't complain about a
template that can't match the desired type category.
diff --git a/gcc/cp/cvt.c b/gcc/cp/cvt.c
index 532e8fd..08c026d 100644
--- a/gcc/cp/cvt.c
+++ b/gcc/cp/cvt.c
@@ -1590,17 +1590,6 @@ build_expr_type_conversion (int desires, tree expr, bool complain)
if (DECL_NONCONVERTING_P (cand))
continue;
- if (TREE_CODE (cand) == TEMPLATE_DECL)
- {
- if (complain)
- {
- error ("ambiguous default type conversion from %qT",
- basetype);
- error (" candidate conversions include %qD", cand);
- }
- return error_mark_node;
- }
-
candidate = non_reference (TREE_TYPE (TREE_TYPE (cand)));
switch (TREE_CODE (candidate))
@@ -1634,11 +1623,23 @@ build_expr_type_conversion (int desires, tree expr, bool complain)
break;
default:
+ /* A wildcard could be instantiated to match any desired
+ type, but we can't deduce the template argument. */
+ if (WILDCARD_TYPE_P (candidate))
+ win = true;
break;
}
if (win)
{
+ if (TREE_CODE (cand) == TEMPLATE_DECL)
+ {
+ if (complain)
+ error ("default type conversion can't deduce template"
+ " argument for %qD", cand);
+ return error_mark_node;
+ }
+
if (winner)
{
tree winner_type
diff --git a/gcc/testsuite/g++.dg/template/delete2.C b/gcc/testsuite/g++.dg/template/delete2.C
new file mode 100644
index 0000000..b6ab380
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/delete2.C
@@ -0,0 +1,26 @@
+// PR c++/58119
+
+template <class T>
+struct A
+{
+ operator T*();
+ template <class U>
+ operator A<U>();
+};
+
+template <class T>
+struct B
+{
+ operator T*();
+ template <class U>
+ operator A<U>*();
+};
+
+int main()
+{
+ A<int> a;
+ delete a;
+
+ B<int> b;
+ delete b; // { dg-error "template|delete" }
+}
