From caadc127fef2a5ce5dddae0d3ac6a582c285baff Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Fri, 6 Aug 2010 14:15:26 +0000
Subject: [PATCH] Remove some incorrect assertions when deduction template
 arguments in a template-argument-list. When template template parameters are
 involved, we won't already have checked the template-argument-list (it may
 not be known yet!). Fixes PR7807.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@110444 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaTemplateDeduction.cpp      |  2 --
 test/SemaTemplate/temp_arg_template.cpp | 18 ++++++++++++++++++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/lib/Sema/SemaTemplateDeduction.cpp b/lib/Sema/SemaTemplateDeduction.cpp
index e677b2666b..65d7f8797d 100644
--- a/lib/Sema/SemaTemplateDeduction.cpp
+++ b/lib/Sema/SemaTemplateDeduction.cpp
@@ -847,7 +847,6 @@ DeduceTemplateArguments(Sema &S,
       return Sema::TDK_NonDeducedMismatch;
     }
 
-    assert(false && "Type/value mismatch");
     Info.FirstArg = Param;
     Info.SecondArg = Arg;
     return Sema::TDK_NonDeducedMismatch;
@@ -868,7 +867,6 @@ DeduceTemplateArguments(Sema &S,
         return DeduceNonTypeTemplateArgument(S, NTTP, Arg.getAsDecl(),
                                              Info, Deduced);
       
-      assert(false && "Type/value mismatch");
       Info.FirstArg = Param;
       Info.SecondArg = Arg;
       return Sema::TDK_NonDeducedMismatch;
diff --git a/test/SemaTemplate/temp_arg_template.cpp b/test/SemaTemplate/temp_arg_template.cpp
index 667122583f..944acacd84 100644
--- a/test/SemaTemplate/temp_arg_template.cpp
+++ b/test/SemaTemplate/temp_arg_template.cpp
@@ -33,3 +33,21 @@ A<f> *a9; // expected-error{{must be a class template}}
 // FIXME: The code below is ill-formed, because of the evil digraph '<:'. 
 // We should provide a much better error message than we currently do.
 // A<::N::Z> *a10;
+
+// PR7807
+namespace N {
+  template <typename, typename = int> 
+  struct X
+  { };
+
+  template <typename ,int> 
+  struct Y
+  { X<int> const_ref(); };
+
+  template <template<typename,int> class TT, typename T, int N> 
+  int operator<<(int, TT<T, N> a) { // expected-note{{candidate template ignored}}
+    0 << a.const_ref(); // expected-error{{invalid operands to binary expression ('int' and 'X<int>')}}
+  }
+
+  void f0( Y<int,1> y){ 1 << y; } // expected-note{{in instantiation of function template specialization 'N::operator<<<Y, int, 1>' requested here}}
+}
-- 
2.40.0