[gnote] Update macro for C++11 detection

[Aurimas Černius <aurimasc src gnome org>]

commit 9880e9bd15e83de11d47e72d070a22df44be58a9
Author: Aurimas Černius <aurisc4 gmail com>
Date:   Fri May 29 19:44:37 2015 +0300

    Update macro for C++11 detection

 m4/ax_cxx_compile_stdcxx_11.m4 |   38 ++++++++++++++++++++++++++++++++++----
 1 files changed, 34 insertions(+), 4 deletions(-)
---
diff --git a/m4/ax_cxx_compile_stdcxx_11.m4 b/m4/ax_cxx_compile_stdcxx_11.m4
index af37acd..229de30 100644
--- a/m4/ax_cxx_compile_stdcxx_11.m4
+++ b/m4/ax_cxx_compile_stdcxx_11.m4
@@ -27,21 +27,29 @@
 #   Copyright (c) 2008 Benjamin Kosnik <bkoz redhat com>
 #   Copyright (c) 2012 Zack Weinberg <zackw panix com>
 #   Copyright (c) 2013 Roy Stogner <roystgnr ices utexas edu>
+#   Copyright (c) 2014, 2015 Google Inc.; contributed by Alexey Sokolov <sokolov google com>
 #
 #   Copying and distribution of this file, with or without modification, are
 #   permitted in any medium without royalty provided the copyright notice
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 3
+#serial 9
 
-m4_define([_AX_CXX_COMPILE_STDCXX_11_testbody], [
+m4_define([_AX_CXX_COMPILE_STDCXX_11_testbody], [[
   template <typename T>
     struct check
     {
       static_assert(sizeof(int) <= sizeof(T), "not big enough");
     };
 
+    struct Base {
+    virtual void f() {}
+    };
+    struct Child : public Base {
+    virtual void f() override {}
+    };
+
     typedef check<check<bool>> right_angle_brackets;
 
     int a;
@@ -52,7 +60,29 @@ m4_define([_AX_CXX_COMPILE_STDCXX_11_testbody], [
     check_type&& cr = static_cast<check_type&&>(c);
 
     auto d = a;
-])
+    auto l = [](){};
+
+    // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae
+    // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function because of this
+    namespace test_template_alias_sfinae {
+        struct foo {};
+
+        template<typename T>
+        using member = typename T::member_type;
+
+        template<typename T>
+        void func(...) {}
+
+        template<typename T>
+        void func(member<T>*) {}
+
+        void test();
+
+        void test() {
+            func<foo>(0);
+        }
+    }
+]])
 
 AC_DEFUN([AX_CXX_COMPILE_STDCXX_11], [dnl
   m4_if([$1], [], [],
@@ -62,7 +92,7 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX_11], [dnl
   m4_if([$2], [], [ax_cxx_compile_cxx11_required=true],
         [$2], [mandatory], [ax_cxx_compile_cxx11_required=true],
         [$2], [optional], [ax_cxx_compile_cxx11_required=false],
-        [m4_fatal([invalid second argument `$2' to AX_CXX_COMPILE_STDCXX_11])])dnl
+        [m4_fatal([invalid second argument `$2' to AX_CXX_COMPILE_STDCXX_11])])
   AC_LANG_PUSH([C++])dnl
   ac_success=no
   AC_CACHE_CHECK(whether $CXX supports C++11 features by default,