Add tests making sure that optional<T>s can be compared at compile time; this functionality was enabled by N3789

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@192051 91177308-0d34-0410-b5e6-96231b3b80d8

test/utilities/optional/optional.relops/equal.pass.cpp

@@ -15,11 +15,25 @@
 #include <type_traits>
 #include <cassert>
 
+#if _LIBCPP_STD_VER > 11
+
+struct X
+{
+    int i_;
+
+    constexpr X(int i) : i_(i) {}
+};
+
+constexpr bool operator == ( const X &rhs, const X &lhs )
+    { return rhs.i_ == lhs.i_ ; }
+    
+#endif
+
 int main()
 {
 #if _LIBCPP_STD_VER > 11
     {
-    typedef int T;
+    typedef X T;
     typedef std::optional<T> O;
     
     constexpr O o1;     // disengaged

test/utilities/optional/optional.relops/less_than.pass.cpp

@@ -22,21 +22,8 @@ struct X
     constexpr X(int i) : i_(i) {}
 };
 
-namespace std
-{
-
-template <>
-struct less<X>
-{
-    constexpr
-    bool
-    operator()(const X& x, const X& y) const
-    {
-        return x.i_ < y.i_;
-    }
-};
-
-}
+constexpr bool operator < ( const X &rhs, const X &lhs )
+    { return rhs.i_ < lhs.i_ ; }
 
 #endif