Here we were getting confused about whether or not pod_tuple has a trivial default constructor. bar inherits the trivial e default constructor; the effect of calling that inherited constructor is equivalent to calling a defaulted default constructor in bar, so let's treat it as such.
Tested x86_64-pc-linux-gnu, applying to trunk. * method.c (trivial_fn_p): Treat an inherited default constructor like a normal default constructor. --- gcc/cp/method.c | 7 ++++++- gcc/testsuite/g++.dg/cpp0x/inh-ctor34.C | 13 +++++++++++++ 2 files changed, 19 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/inh-ctor34.C diff --git a/gcc/cp/method.c b/gcc/cp/method.c index fef19e18196..e20a88febdc 100644 --- a/gcc/cp/method.c +++ b/gcc/cp/method.c @@ -458,7 +458,12 @@ trivial_fn_p (tree fn) /* If fn is a clone, get the primary variant. */ if (tree prim = DECL_CLONED_FUNCTION (fn)) fn = prim; - return type_has_trivial_fn (DECL_CONTEXT (fn), special_function_p (fn)); + special_function_kind sfk = special_function_p (fn); + /* An inherited default constructor is equivalent to a non-inherited default + constructor, so let it be trivial. */ + if (sfk == sfk_inheriting_constructor && default_ctor_p (fn)) + sfk = sfk_constructor; + return type_has_trivial_fn (DECL_CONTEXT (fn), sfk); } /* PARM is a PARM_DECL for a function which we want to forward to another diff --git a/gcc/testsuite/g++.dg/cpp0x/inh-ctor34.C b/gcc/testsuite/g++.dg/cpp0x/inh-ctor34.C new file mode 100644 index 00000000000..9afc0e9e536 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/inh-ctor34.C @@ -0,0 +1,13 @@ +// PR c++/92594 +// { dg-do compile { target c++11 } } + +template <typename _Head> struct tuple { + tuple() : _M_head_impl() {} + _Head _M_head_impl; +}; +template <typename type0> struct pod_tuple { type0 _head; }; +struct e {}; +struct bar : e { + using e::e; +}; +int main() { tuple<pod_tuple<bar>> a; } base-commit: 03e87724864a17e22c9b692cc0caa014e9dba6b1 -- 2.18.1