In this case, the copy constructor is trivial, so we don't complain
about having a non-trivial copy constructor. But we should still be
doing the lvalue-rvalue conversion, which strictly speaking involves a
copy constructor call.
Tested x86_64-pc-linux-gnu, applying to trunk.
commit a3138b14669986fe312a9579e79edcf091026eec
Author: Jason Merrill <ja...@redhat.com>
Date: Mon May 23 13:52:01 2011 -0400
PR c++/49102
* call.c (convert_arg_to_ellipsis): Call force_rvalue.
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 8503f5e..ff3dc06 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -5905,10 +5905,13 @@ convert_arg_to_ellipsis (tree arg)
/* In a template (or ill-formed code), we can have an incomplete type
even after require_complete_type, in which case we don't know
whether it has trivial copy or not. */
- && COMPLETE_TYPE_P (arg_type)
- && (type_has_nontrivial_copy_init (arg_type)
- || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (arg_type)))
+ && COMPLETE_TYPE_P (arg_type))
{
+ /* Build up a real lvalue-to-rvalue conversion in case the
+ copy constructor is trivial but not callable. */
+ if (CLASS_TYPE_P (arg_type))
+ force_rvalue (arg, tf_warning_or_error);
+
/* [expr.call] 5.2.2/7:
Passing a potentially-evaluated argument of class type (Clause 9)
with a non-trivial copy constructor or a non-trivial destructor
@@ -5920,7 +5923,9 @@ convert_arg_to_ellipsis (tree arg)
If the call appears in the context of a sizeof expression,
it is not potentially-evaluated. */
- if (cp_unevaluated_operand == 0)
+ if (cp_unevaluated_operand == 0
+ && (type_has_nontrivial_copy_init (arg_type)
+ || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (arg_type)))
error ("cannot pass objects of non-trivially-copyable "
"type %q#T through %<...%>", arg_type);
}
diff --git a/gcc/testsuite/g++.dg/cpp0x/defaulted28.C b/gcc/testsuite/g++.dg/cpp0x/defaulted28.C
new file mode 100644
index 0000000..15caef6
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/defaulted28.C
@@ -0,0 +1,15 @@
+// PR c++/49102
+// { dg-options -std=c++0x }
+
+struct A {
+ A() = default;
+
+private:
+ A(A const&) = default; // { dg-error "private" }
+};
+
+void f(...) { }
+int main() {
+ A a;
+ f(a); // { dg-error "this context" }
+}
