📝 fixing documentation #867

The example in the documentation on how to "force" an array of arrays was wrong since the first release. Fixed the documentation and added checks for the README unit tests.

README.md

@@ -160,7 +160,7 @@ json empty_object_implicit = json({});
 json empty_object_explicit = json::object();
 
 // a way to express an _array_ of key/value pairs [["currency", "USD"], ["value", 42.99]]
-json array_not_object = { json::array({"currency", "USD"}), json::array({"value", 42.99}) };
+json array_not_object = json::array({ {"currency", "USD"}, {"value", 42.99} });
 ```
 
 

src/json.hpp

@@ -3646,12 +3646,12 @@ class iter_impl
 
   public:
 
-	/// The std::iterator class template (used as a base class to provide typedefs) is deprecated in C++17. 
-	/// The C++ Standard has never required user-defined iterators to derive from std::iterator. 
-	/// A user-defined iterator should provide publicly accessible typedefs named 
-	/// iterator_category, value_type, difference_type, pointer, and reference. 
-	/// Note that value_type is required to be non-const, even for constant iterators.
-	using iterator_category = std::bidirectional_iterator_tag;
+    /// The std::iterator class template (used as a base class to provide typedefs) is deprecated in C++17.
+    /// The C++ Standard has never required user-defined iterators to derive from std::iterator.
+    /// A user-defined iterator should provide publicly accessible typedefs named
+    /// iterator_category, value_type, difference_type, pointer, and reference.
+    /// Note that value_type is required to be non-const, even for constant iterators.
+    using iterator_category = std::bidirectional_iterator_tag;
 
     /// the type of the values when the iterator is dereferenced
     using value_type = typename BasicJsonType::value_type;

test/src/unit-readme.cpp

@@ -100,13 +100,20 @@ TEST_CASE("README", "[hide]")
         {
             // ways to express the empty array []
             json empty_array_implicit = {{}};
+            CHECK(empty_array_implicit.is_array());
             json empty_array_explicit = json::array();
+            CHECK(empty_array_explicit.is_array());
 
             // a way to express the empty object {}
             json empty_object_explicit = json::object();
+            CHECK(empty_object_explicit.is_object());
 
             // a way to express an _array_ of key/value pairs [["currency", "USD"], ["value", 42.99]]
-            json array_not_object = { json::array({"currency", "USD"}), json::array({"value", 42.99}) };
+            json array_not_object = json::array({ {"currency", "USD"}, {"value", 42.99} });
+            CHECK(array_not_object.is_array());
+            CHECK(array_not_object.size() == 2);
+            CHECK(array_not_object[0].is_array());
+            CHECK(array_not_object[1].is_array());
         }
 
         {