Implement P0522R0, matching of template template arguments.

gcc/c-family/
	* c.opt (-fnew-ttp-matching): New flag.
	* c-opts.c (c_common_post_options): Default on if -std=c++1z.
gcc/cp/
	* pt.c (coerce_template_template_parms): Allow a template argument
	that's less specialized than the parameter.
	(unify_bound_ttp_args): Adjust parm's args to apply to arg's
	template.
	(coerce_template_args_for_ttp): Split out from
	lookup_template_class_1.
	(coerce_ttp_args_for_tta, store_defaulted_ttp)
	(lookup_defaulted_ttp, add_defaults_to_ttp): New.
	(process_partial_specialization): Set DECL_CONTEXT of
	template template-parameters.
	(coerce_template_parms): Only inform when complain.
	(expand_template_argument_pack): Handle error_mark_node.
	(convert_template_argument, template_args_equal, unify): Handle
	any_targ_node.
	* cp-tree.h (enum cp_tree_index): Add CPTI_ANY_TARG.
	(any_targ_node): New.
	* decl.c (cxx_init_decl_processing): Set it.
	* name-lookup.c (consider_binding_level): Ignore names with embedded
	spaces.

From-SVN: r243871

1 files changed, 5 insertions, 0 deletions

diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 89bb9b2..ef6265e 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -1140,6 +1140,8 @@ enum cp_tree_index
 
     CPTI_ALIGN_TYPE,
 
+    CPTI_ANY_TARG,
+
     CPTI_MAX
 };
 
@@ -1245,6 +1247,9 @@ extern GTY(()) tree cp_global_trees[CPTI_MAX];
 
 #define keyed_classes			cp_global_trees[CPTI_KEYED_CLASSES]
 
+/* A node which matches any template argument.  */
+#define any_targ_node			cp_global_trees[CPTI_ANY_TARG]
+
 /* Node to indicate default access. This must be distinct from the
    access nodes in tree.h.  */