removed std::out output from test cases

test/src/unit.cpp

@@ -10308,6 +10308,11 @@ TEST_CASE("parser class")
 
 TEST_CASE("README", "[hide]")
 {
+    {
+        // redirect std::cout for the README file
+        auto old_cout_buffer = std::cout.rdbuf();
+        std::ostringstream new_stream;
+        std::cout.rdbuf(new_stream.rdbuf());
         {
             // create an empty structure (null)
             json j;
@@ -10556,6 +10561,10 @@ TEST_CASE("README", "[hide]")
             //   { "op":"add","path":"/foo","value":"bar" }
             // ]
         }
+
+        // restore old std::cout
+        std::cout.rdbuf(old_cout_buffer);
+    }
 }
 
 TEST_CASE("algorithms")