From 79a9afa50f86669be04a3d3ef3068ddd43612f05 Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Tue, 12 Jun 2018 23:33:06 -0400
Subject: [PATCH] PR c++/86098 - ICE with template placeholder for TTP.

	* typeck.c (structural_comptypes) [TEMPLATE_TYPE_PARM]: Check
	CLASS_PLACEHOLDER_TEMPLATE.

From-SVN: r261536
---
 gcc/cp/ChangeLog                               |  6 ++++++
 gcc/cp/typeck.c                                |  5 +++++
 gcc/testsuite/g++.dg/cpp1z/class-deduction58.C | 16 ++++++++++++++++
 3 files changed, 27 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/cpp1z/class-deduction58.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 05105ae7cfe..4c23d574bf1 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2018-06-12  Jason Merrill  <jason@redhat.com>
+
+	PR c++/86098 - ICE with template placeholder for TTP.
+	* typeck.c (structural_comptypes) [TEMPLATE_TYPE_PARM]: Check
+	CLASS_PLACEHOLDER_TEMPLATE.
+
 2018-06-12  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	* decl2.c (coerce_new_type, coerce_delete_type): Add location_t
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index 9febdb908ae..b033afd9884 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -1375,6 +1375,11 @@ structural_comptypes (tree t1, tree t2, int strict)
 	 template parameters set, they can't be equal.  */
       if (!comp_template_parms_position (t1, t2))
 	return false;
+      /* If T1 and T2 don't represent the same class template deduction,
+         they aren't equal.  */
+      if (CLASS_PLACEHOLDER_TEMPLATE (t1)
+	  != CLASS_PLACEHOLDER_TEMPLATE (t2))
+	return false;
       /* Constrained 'auto's are distinct from parms that don't have the same
 	 constraints.  */
       if (!equivalent_placeholder_constraints (t1, t2))
diff --git a/gcc/testsuite/g++.dg/cpp1z/class-deduction58.C b/gcc/testsuite/g++.dg/cpp1z/class-deduction58.C
new file mode 100644
index 00000000000..82c3f83710f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/class-deduction58.C
@@ -0,0 +1,16 @@
+// PR c++/86098
+// { dg-additional-options -std=c++17 }
+
+template <class _Res> class future;
+template <class T> T&& declval();
+
+template<template <class...> class T>
+struct construct_deduced {
+  template <class... AN>
+  using deduced_t = decltype(T{declval<AN>()...});
+  template<class... AN>
+  deduced_t<AN...> operator()(AN&&... an) const;
+};
+
+template<class T>
+future<T> future_from(T singleSender);
-- 
2.30.2