re PR c++/57526 (use of X before deduction of auto error for seemingly good code)

	PR c++/57526
	* semantics.c (lambda_capture_field_type): Build a DECLTYPE_TYPE
	if the variable type uses 'auto'.

From-SVN: r200844

gcc/cp/ChangeLog

 2013-07-09  Jason Merrill  <jason@redhat.com>
 
+	PR c++/57526
+	* semantics.c (lambda_capture_field_type): Build a DECLTYPE_TYPE
+	if the variable type uses 'auto'.
+
 	PR c++/57437
 	* typeck.c (check_return_expr): Lambda proxies aren't eligible
 	for nrv or return by move.

gcc/cp/semantics.c

@@ -9177,7 +9177,7 @@ lambda_capture_field_type (tree expr, bool explicit_init_p)
     }
   else
     type = non_reference (unlowered_expr_type (expr));
-  if (!type || WILDCARD_TYPE_P (type))
+  if (!type || WILDCARD_TYPE_P (type) || type_uses_auto (type))
     {
       type = cxx_make_type (DECLTYPE_TYPE);
       DECLTYPE_TYPE_EXPR (type) = expr;

gcc/testsuite/g++.dg/cpp0x/lambda/lambda-auto3.C

+// PR c++/57526
+// { dg-require-effective-target c++11 }
+
+template<class T>
+struct A
+{
+  void bar( ) { }
+
+  void foo( )
+  {
+    auto* this_ptr = this;
+    auto lc = [&]( )
+      {
+	this_ptr->bar();
+      };
+    lc();
+  }
+};
+
+int main()
+{
+  A<int> a;
+  a.foo();
+}