From b388069f077c2fd50c706755b927b96d95e5cf56 Mon Sep 17 00:00:00 2001
From: Daniel Parker <danielaparker@yahoo.com>
Date: Fri, 3 Nov 2023 15:41:00 -0400
Subject: [PATCH] make_expression<json>

---
 include/jsoncons/detail/span.hpp              |  2 +-
 include/jsoncons_ext/jsonpath/json_query.hpp  | 10 +++---
 .../jsonpath/jsonpath_expression.hpp          | 36 ++++++++++++++-----
 3 files changed, 34 insertions(+), 14 deletions(-)

diff --git a/include/jsoncons/detail/span.hpp b/include/jsoncons/detail/span.hpp
index be6c84a464..c5eb171744 100644
--- a/include/jsoncons/detail/span.hpp
+++ b/include/jsoncons/detail/span.hpp
@@ -31,7 +31,7 @@ namespace detail
     {
     public:
         using element_type = T;
-        using value_type = typename std::remove_volatile<typename std::remove_const<T>::type>::type;
+        using value_type = typename std::remove_const<T>::type;
         using size_type = std::size_t;
         using difference_type = std::ptrdiff_t;
         using pointer = T*;
diff --git a/include/jsoncons_ext/jsonpath/json_query.hpp b/include/jsoncons_ext/jsonpath/json_query.hpp
index 5e940cc29d..d59216bbe2 100644
--- a/include/jsoncons_ext/jsonpath/json_query.hpp
+++ b/include/jsoncons_ext/jsonpath/json_query.hpp
@@ -62,7 +62,7 @@ namespace jsonpath {
         json_replace(Json& instance, const typename Json::string_view_type& path, T&& new_value,
                      const custom_functions<Json>& funcs = custom_functions<Json>())
     {
-        using jsonpath_traits_type = jsoncons::jsonpath::jsonpath_traits<Json, Json&>;
+        using jsonpath_traits_type = jsoncons::jsonpath::legacy_jsonpath_traits<Json, Json&>;
 
         using value_type = typename jsonpath_traits_type::value_type;
         using reference = typename jsonpath_traits_type::reference;
@@ -88,7 +88,7 @@ namespace jsonpath {
             Json& instance, const typename Json::string_view_type& path, T&& new_value,
             const custom_functions<Json>& funcs = custom_functions<Json>())
     {
-        using jsonpath_traits_type = jsoncons::jsonpath::jsonpath_traits<Json, Json&>;
+        using jsonpath_traits_type = jsoncons::jsonpath::legacy_jsonpath_traits<Json, Json&>;
 
         using value_type = typename jsonpath_traits_type::value_type;
         using reference = typename jsonpath_traits_type::reference;
@@ -113,7 +113,7 @@ namespace jsonpath {
     json_replace(Json& instance, const typename Json::string_view_type& path , BinaryCallback callback, 
                  const custom_functions<Json>& funcs = custom_functions<Json>())
     {
-        using jsonpath_traits_type = jsoncons::jsonpath::jsonpath_traits<Json, Json&>;
+        using jsonpath_traits_type = jsoncons::jsonpath::legacy_jsonpath_traits<Json, Json&>;
 
         using value_type = typename jsonpath_traits_type::value_type;
         using reference = typename jsonpath_traits_type::reference;
@@ -140,7 +140,7 @@ namespace jsonpath {
         Json& instance, const typename Json::string_view_type& path , BinaryCallback callback, 
         const custom_functions<Json>& funcs = custom_functions<Json>())
     {
-        using jsonpath_traits_type = jsoncons::jsonpath::jsonpath_traits<Json, Json&>;
+        using jsonpath_traits_type = jsoncons::jsonpath::legacy_jsonpath_traits<Json, Json&>;
 
         using value_type = typename jsonpath_traits_type::value_type;
         using reference = typename jsonpath_traits_type::reference;
@@ -166,7 +166,7 @@ namespace jsonpath {
     typename std::enable_if<extension_traits::is_unary_function_object<UnaryCallback,Json>::value,void>::type
     json_replace(Json& instance, const typename Json::string_view_type& path , UnaryCallback callback)
     {
-        using jsonpath_traits_type = jsoncons::jsonpath::jsonpath_traits<Json, Json&>;
+        using jsonpath_traits_type = jsoncons::jsonpath::legacy_jsonpath_traits<Json, Json&>;
 
         using value_type = typename jsonpath_traits_type::value_type;
         using reference = typename jsonpath_traits_type::reference;
diff --git a/include/jsoncons_ext/jsonpath/jsonpath_expression.hpp b/include/jsoncons_ext/jsonpath/jsonpath_expression.hpp
index bfc66bf008..14ff699edc 100644
--- a/include/jsoncons_ext/jsonpath/jsonpath_expression.hpp
+++ b/include/jsoncons_ext/jsonpath/jsonpath_expression.hpp
@@ -2484,12 +2484,13 @@ namespace detail {
     } // namespace detail
 
     template <class Json, class JsonReference = const Json&>
-    struct jsonpath_traits
+    struct legacy_jsonpath_traits
     {
         using char_type = typename Json::char_type;
         using string_type = typename Json::string_type;
         using string_view_type = typename Json::string_view_type;
-        using value_type = typename std::remove_volatile<typename std::remove_const<Json>::type>::type;
+        using element_type = Json;
+        using value_type = typename std::remove_cv<Json>::type;
         using reference = JsonReference;
         using const_reference = const value_type&;
         using pointer = typename std::conditional<std::is_const<typename std::remove_reference<reference>::type>::value, typename Json::const_pointer, typename Json::pointer>::type;
@@ -2501,11 +2502,30 @@ namespace detail {
         using path_pointer = const path_node_type*;
     };
 
+    template <class Json>
+    struct jsonpath_traits
+    {
+        using char_type = typename Json::char_type;
+        using string_type = typename Json::string_type;
+        using string_view_type = typename Json::string_view_type;
+        using element_type = Json;
+        using value_type = typename std::remove_cv<Json>::type;
+        using reference = Json&;
+        using const_reference = const Json&;
+        using pointer = typename std::conditional<std::is_const<typename std::remove_reference<reference>::type>::value, typename Json::const_pointer, typename Json::pointer>::type;
+        using allocator_type = typename value_type::allocator_type;
+        using evaluator_type = typename jsoncons::jsonpath::detail::jsonpath_evaluator<value_type, reference>;
+        using path_node_type = path_node<string_type>;
+        using json_location_type = json_location<string_type>;
+        using path_expression_type = jsoncons::jsonpath::detail::path_expression<value_type,reference>;
+        using path_pointer = const path_node_type*;
+    };
+
     template <class Json,class JsonReference = const Json&, class TempAllocator=std::allocator<char>>
     class jsonpath_expression
     {
     public:
-        using jsonpath_traits_type = jsoncons::jsonpath::jsonpath_traits<Json, JsonReference>;
+        using jsonpath_traits_type = jsoncons::jsonpath::legacy_jsonpath_traits<Json, JsonReference>;
 
         using allocator_type = typename jsonpath_traits_type::allocator_type;
         using evaluator_type = typename jsonpath_traits_type::evaluator_type;
@@ -2587,7 +2607,7 @@ namespace detail {
     class update_expression
     {
     public:
-        using jsonpath_traits_type = jsoncons::jsonpath::jsonpath_traits<Json, JsonReference>;
+        using jsonpath_traits_type = jsoncons::jsonpath::legacy_jsonpath_traits<Json, JsonReference>;
 
         using allocator_type = typename jsonpath_traits_type::allocator_type;
         using evaluator_type = typename jsonpath_traits_type::evaluator_type;
@@ -2690,7 +2710,7 @@ namespace detail {
         const typename Json::string_view_type& path, 
         const custom_functions<Json>& functions = custom_functions<Json>())
     {
-        using jsonpath_traits_type = jsoncons::jsonpath::jsonpath_traits<Json>;
+        using jsonpath_traits_type = jsoncons::jsonpath::legacy_jsonpath_traits<Json>;
 
         using value_type = typename jsonpath_traits_type::value_type;
         using reference = typename jsonpath_traits_type::reference;
@@ -2711,7 +2731,7 @@ namespace detail {
         const typename Json::string_view_type& path, 
         const custom_functions<Json>& functions, std::error_code& ec)
     {
-        using jsonpath_traits_type = jsoncons::jsonpath::jsonpath_traits<Json>;
+        using jsonpath_traits_type = jsoncons::jsonpath::legacy_jsonpath_traits<Json>;
 
         using value_type = typename jsonpath_traits_type::value_type;
         using reference = typename jsonpath_traits_type::reference;
@@ -2730,7 +2750,7 @@ namespace detail {
     auto make_update_expression(const typename Json::string_view_type& path,
         const jsoncons::jsonpath::custom_functions<Json>& funcs = jsoncons::jsonpath::custom_functions<Json>())
     {
-        using jsonpath_traits_type = jsoncons::jsonpath::jsonpath_traits<Json, Json&>;
+        using jsonpath_traits_type = jsoncons::jsonpath::jsonpath_traits<Json>;
 
         using value_type = typename jsonpath_traits_type::value_type;
         using reference = typename jsonpath_traits_type::reference;
@@ -2748,7 +2768,7 @@ namespace detail {
         const typename Json::string_view_type& path,
         const jsoncons::jsonpath::custom_functions<Json>& funcs, std::error_code& ec)
     {
-        using jsonpath_traits_type = jsoncons::jsonpath::jsonpath_traits<Json, Json&>;
+        using jsonpath_traits_type = jsoncons::jsonpath::jsonpath_traits<Json>;
 
         using value_type = typename jsonpath_traits_type::value_type;
         using reference = typename jsonpath_traits_type::reference;