Googlemock has some tuples containing lvalue refs in its unit tests.

These tuples are created with make_tuple, which is given temporaries.
The make_tuple is in a function argument list.

A possibly overzealous static_assert in libc++'s std::tuple ctor
is firing in our 'Perform(make_tuple("hi"))' calls, so
we can't use its make_tuple here. Instead we will use
explicitly-constructed tuples constructed from non-temporary strings.

Workaround for llvm bug:
    https://llvm.org/bugs/show_bug.cgi?id=20855

An alternative to https://github.com/google/googletest/pull/580 .

googlemock/test/gmock-more-actions_test.cc

@@ -327,7 +327,9 @@ TEST(InvokeTest, FunctionThatTakes10Arguments) {
 TEST(InvokeTest, FunctionWithUnusedParameters) {
   Action<int(int, int, double, const string&)> a1 =
       Invoke(SumOfFirst2);
-  EXPECT_EQ(12, a1.Perform(make_tuple(10, 2, 5.6, string("hi"))));
+  string s("hi");
+  EXPECT_EQ(12, a1.Perform(
+    tuple<int, int, double, const string&>(10, 2, 5.6, s)));
 
   Action<int(int, int, bool, int*)> a2 =
       Invoke(SumOfFirst2);
@@ -379,7 +381,8 @@ TEST(InvokeMethodTest, Binary) {
   Foo foo;
   Action<string(const string&, char)> a = Invoke(&foo, &Foo::Binary);
   string s("Hell");
-  EXPECT_EQ("Hello", a.Perform(make_tuple(s, 'o')));
+  EXPECT_EQ("Hello", a.Perform(
+      tuple<const string&, char>(s, 'o')));
 }
 
 // Tests using Invoke() with a ternary method.