Set properties when constructing interfaces.

Make use of new sdbusplus support for passing a map
of properties and their values to the interface
constructor.

Change-Id: Ib0dd406fd80c89acb723e3a376af26ba57b53d27
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>

1 files changed, 62 insertions, 0 deletions

diff --git a/utils.hpp b/utils.hpp
index 33de439..60119be 100644
--- a/utils.hpp
+++ b/utils.hpp
@@ -6,7 +6,69 @@ namespace inventory
 {
 namespace manager
 {
+/** @struct MakeVariantVisitor
+ *  @brief Return a variant if the visited type is a possible variant type.
+ *
+ *  @tparam V - The desired variant type.
+ */
+template <typename V>
+struct MakeVariantVisitor
+{
+    /** @struct Make
+     *  @brief Return variant visitor.
+     *
+     *  @tparam T - The variant type to return.
+     *  @tparam Arg - The type being visited in the source variant.
+     *  @tparam Enable - Overload resolution removal.
+     */
+    template <typename T, typename Arg, typename Enable = void>
+    struct Make
+    {
+        static auto make(Arg&& arg)
+        {
+            throw sdbusplus::message::variant_ns::bad_variant_access(
+                "in MakeVariantVisitor");
+            return T();
+        }
+    };
+
+    /** @struct Make
+     *  @brief Return variant visitor.
+     *
+     *  struct Make specialization if Arg is in T (int -> variant<int, char>).
+     */
+    template <typename T, typename Arg>
+    struct Make<T, Arg,
+               typename std::enable_if<std::is_convertible<Arg, T>::value>::type>
+    {
+        static auto make(Arg&& arg)
+        {
+            return T(std::forward<Arg>(arg));
+        }
+    };
 
+    /** @brief Make variant visitor.  */
+    template <typename Arg>
+    auto operator()(Arg&& arg) const
+    {
+        return Make<V, Arg>::make(arg);
+    }
+};
+
+/** @brief Convert variants with different contained types.
+ *
+ *  @tparam V - The desired variant type.
+ *  @tparam Arg - The source variant type.
+ *
+ *  @param[in] v - The source variant.
+ *  @returns - The converted variant.
+ */
+template <typename V, typename Arg>
+auto convertVariant(Arg&& v)
+{
+    return sdbusplus::message::variant_ns::apply_visitor(
+               MakeVariantVisitor<V>(), v);
+}
 } // namespace manager
 } // namespace inventory
 } // namespace phosphor