Update json_rpc example to work on both versions of Boost.JSON

Author: pdimov

example/json_rpc.cpp

@@ -34,7 +34,7 @@ template<class C1, class C2, class R, class... A>
 
 template<class C>
   boost::json::value
-    call( C & c, boost::string_view method, boost::json::value const & args )
+    call( C & c, boost::string_view method, boost::json::array const & args )
 {
     using Fd = boost::describe::describe_members<C,
         boost::describe::mod_public | boost::describe::mod_function>;
@@ -46,7 +46,7 @@ template<class C>
 
         if( !found && method == D.name)
         {
-            result = call_impl( c, D.pointer, args.as_array() );
+            result = call_impl( c, D.pointer, args );
             found = true;
         }
 
@@ -80,6 +80,6 @@ BOOST_DESCRIBE_STRUCT(Object, (), (greet, add))
 int main()
 {
     Object obj;
-    std::cout << call( obj, "greet", {{ "world" }} ) << std::endl;
-    std::cout << call( obj, "add", {{ 1, 2 }} ) << std::endl;
+    std::cout << call( obj, "greet", { "world" } ) << std::endl;
+    std::cout << call( obj, "add", { 1, 2 } ) << std::endl;
 }