Sub objects

Signed-off-by: TymianekPL <tymi@tymi.org>

Author: TymianekPL

Test/Test.cpp

@@ -7,6 +7,10 @@ int main()
 	std::println("{}", object);
 	object["test1"] = "Hello World";
 	object["test2"] = 123.0;
+	object["sub"]["veryNested"] = 6.0;
+
 	std::println("{}", object);
 	std::println("object[\"test1\"] = {}", object["test1"]);
+	const std::string test = object["test1"];
+	std::println("test = {}", test);
 }

cppjson/include/cppjson/object.hpp

@@ -68,12 +68,14 @@ namespace cppjson
 			explicit ObjectProxy(JsonObject& object) : _object(std::ref(object)) {}
 
 			template <typename T>
+				requires (!std::same_as<std::remove_cvref_t<T>, JsonObject>)
 			explicit(false) operator T&()
 			{
 				return this->_object.get().As<T>();
 			}
 
 			template <typename T>
+				requires (!std::same_as<std::remove_cvref_t<T>, JsonObject>)
 			explicit(false) operator const T&() const
 			{
 				return this->_object.get().As<T>();
@@ -90,6 +92,8 @@ namespace cppjson
 			{
 				return static_cast<std::string&>(*this) = std::string{ str };
 			}
+ 
+			ObjectProxy operator[](const std::string& key);
 		private:
 			std::reference_wrapper<JsonObject> _object;
 
@@ -106,6 +110,8 @@ namespace cppjson
 			{
 				return this->_object.get().As<T>();
 			}
+
+			ConstObjectProxy operator[](const std::string& key) const;
 		private:
 			std::reference_wrapper<const JsonObject> _object;
 
@@ -127,10 +133,12 @@ namespace cppjson
 	  private:
 		std::unordered_map<std::string, JsonObject> _nodes{};
 
+		friend struct std::formatter<cppjson::JsonObject>;
 		friend struct std::formatter<cppjson::Object>;
 	};
 } // namespace cppjson
 
+
 template <>
 struct std::formatter<cppjson::JsonObject>
 {
@@ -144,54 +152,73 @@ struct std::formatter<cppjson::JsonObject>
 		case cppjson::JsonType::Bool: return std::format_to(context.out(), "{}", object.DangerousAs<bool>());
 		case cppjson::JsonType::Number: return std::format_to(context.out(), "{}", object.DangerousAs<double>());
 		case cppjson::JsonType::String: return std::format_to(context.out(), "\"{}\"", object.DangerousAs<std::string>());
+		case cppjson::JsonType::Object:
+		{
+			const auto& node = object.DangerousAs<cppjson::Object>();
+
+			std::string built = "{ ";
+			for (const auto& [key, value] : node._nodes)
+				built += std::format("\"{}\": {}, ", key, value);
+
+			if (!node._nodes.empty()) // remove trailing commas
+			{
+				built.pop_back();
+				built.pop_back();
+				built += " }";
+			}
+			else built += "}";
+
+			return std::format_to(context.out(), "{}", built);
+		}
 		}
 
 		throw std::logic_error("Unknown type");
 	}
 };
 
 template <>
-struct std::formatter<cppjson::Object::ObjectProxy>
+struct std::formatter<cppjson::Object>
 {
 	constexpr auto parse(std::format_parse_context& context) { return context.begin(); }
 
-	auto format(const cppjson::Object::ObjectProxy& object, std::format_context& context) const
+	auto format(const cppjson::Object& object, std::format_context& context) const
 	{
-		return std::format_to(context.out(), "{}", object._object.get());
+		std::string built = "{ ";
+		for (const auto& [key, value] : object._nodes)
+			built += std::format("\"{}\": {}, ", key, value);
+		
+		if (!object._nodes.empty()) // remove trailing commas
+		{
+			built.pop_back();
+			built.pop_back();
+			built += " }";
+		}
+		else built += "}";
+
+		return std::format_to(context.out(), "{}", built);
 	}
 };
 
 
 template <>
-struct std::formatter<cppjson::Object::ConstObjectProxy>
+struct std::formatter<cppjson::Object::ObjectProxy>
 {
 	constexpr auto parse(std::format_parse_context& context) { return context.begin(); }
 
-	auto format(const cppjson::Object::ConstObjectProxy& object, std::format_context& context) const
+	auto format(const cppjson::Object::ObjectProxy& object, std::format_context& context) const
 	{
 		return std::format_to(context.out(), "{}", object._object.get());
 	}
 };
 
+
 template <>
-struct std::formatter<cppjson::Object>
+struct std::formatter<cppjson::Object::ConstObjectProxy>
 {
 	constexpr auto parse(std::format_parse_context& context) { return context.begin(); }
 
-	auto format(const cppjson::Object& object, std::format_context& context) const
+	auto format(const cppjson::Object::ConstObjectProxy& object, std::format_context& context) const
 	{
-		std::string built = "{ ";
-		for (const auto& [key, value] : object._nodes)
-			built += std::format("\"{}\": {}, ", key, value);
-		
-		if (!object._nodes.empty()) // remove trailing commas
-		{
-			built.pop_back();
-			built.pop_back();
-			built += " }";
-		}
-		else built += "}";
-
-		return std::format_to(context.out(), "{}", built);
+		return std::format_to(context.out(), "{}", object._object.get());
 	}
 };

cppjson/src/object.cpp

@@ -119,3 +119,14 @@ const std::nullptr_t& cppjson::JsonObject::As<std::nullptr_t>() const noexcept(f
 	if (this->_dataType != JsonType::Null) throw std::logic_error("Cannot convert this object to a null");
 	return DangerousAs<std::nullptr_t>();
 }
+
+cppjson::Object::ObjectProxy cppjson::Object::ObjectProxy::operator[](const std::string& key)
+{
+	return ObjectProxy{ this->_object.get().As<Object>()[key] };
+}
+
+
+cppjson::Object::ConstObjectProxy cppjson::Object::ConstObjectProxy::operator[](const std::string& key) const
+{
+	return ConstObjectProxy{ this->_object.get().As<Object>()[key] };
+}