Tested x86_64-pc-linux-gnu, applying to trunk. -- 8< --
This function needs to handle this case like convert_template_argument. PR c++/58538 gcc/cp/ChangeLog: * semantics.cc (check_template_template_default_arg): Check maybe_get_template_decl_from_type_decl. gcc/testsuite/ChangeLog: * g++.dg/template/ttp7.C: Remove expected error. --- gcc/cp/semantics.cc | 9 +++++++-- gcc/testsuite/g++.dg/template/ttp7.C | 2 +- 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc index d67a9b26719..57dd7b66da8 100644 --- a/gcc/cp/semantics.cc +++ b/gcc/cp/semantics.cc @@ -3468,8 +3468,13 @@ check_template_template_default_arg (tree argument) && TREE_CODE (argument) != UNBOUND_CLASS_TEMPLATE) { if (TREE_CODE (argument) == TYPE_DECL) - error ("invalid use of type %qT as a default value for a template " - "template-parameter", TREE_TYPE (argument)); + { + if (tree t = maybe_get_template_decl_from_type_decl (argument)) + if (TREE_CODE (t) == TEMPLATE_DECL) + return t; + error ("invalid use of type %qT as a default value for a template " + "template-parameter", TREE_TYPE (argument)); + } else error ("invalid default argument for a template template parameter"); return error_mark_node; diff --git a/gcc/testsuite/g++.dg/template/ttp7.C b/gcc/testsuite/g++.dg/template/ttp7.C index 0bcaa8f7292..672077e7e7d 100644 --- a/gcc/testsuite/g++.dg/template/ttp7.C +++ b/gcc/testsuite/g++.dg/template/ttp7.C @@ -11,6 +11,6 @@ template<template<int> class = A<0> > struct B2 {}; // { dg-error "as a default template <typename T> struct S { - template <template <typename> class = S> struct I1 {}; // { dg-error "as a default value" } + template <template <typename> class = S> struct I1 {}; // PR c++/58538 template <template <typename> class = ::S> struct I2 {}; }; base-commit: 9e44a9932c11f028269f3aa7e3031e703d151b0b prerequisite-patch-id: dc293188137e8f94cea3b5c135e62efad8fec595 prerequisite-patch-id: 30ba81cfc50ea4cae63d361169fda721504d06f5 -- 2.31.1