Patchwork C++ PATCH for c++/55680 (wrong error for lambda initializing data member specialization)

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Submitter Jason Merrill
Date Feb. 14, 2013, 1:55 p.m.
Message ID <511CECC8.2050407@redhat.com>
Download mbox | patch
Permalink /patch/220448/
State New
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Comments

Jason Merrill - Feb. 14, 2013, 1:55 p.m.
When we have a lambda-expression in the initializer for a specialization 
of a class template static data member, we end up in 
maybe_process_partial_specialization, which sees that 
processing_specialization is set and concludes that we're trying to 
specialize the lambda.  But we aren't.

Tested x86_64-pc-linux-gnu, applying to trunk.

Patch

commit 1631ee6dca428836c7733e5d78e8644af2058ae7
Author: Jason Merrill <jason@redhat.com>
Date:   Wed Feb 13 13:25:20 2013 -0500

    	PR c++/55680
    	* pt.c (maybe_process_partial_specialization): A lambda
    	isn't what's being specialized.

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 2aadd4d..bd44fde 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -802,6 +802,11 @@  maybe_process_partial_specialization (tree type)
   if (type == error_mark_node)
     return error_mark_node;
 
+  /* A lambda that appears in specialization context is not itself a
+     specialization.  */
+  if (CLASS_TYPE_P (type) && CLASSTYPE_LAMBDA_EXPR (type))
+    return type;
+
   if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
     {
       error ("name of class shadows template template parameter %qD",
diff --git a/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-template8.C b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-template8.C
new file mode 100644
index 0000000..720941d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-template8.C
@@ -0,0 +1,7 @@ 
+// PR c++/55680
+// { dg-do compile { target c++11 } }
+
+template <class T> struct X {
+    static void (* code ) ();
+};
+template <> void (* X<int>::code ) () = [](){};