Provide accessors into json_pointer

include/nlohmann/detail/json_pointer.hpp

@@ -19,6 +19,9 @@ class json_pointer
     friend class basic_json;
 
   public:
+    typedef std::vector<std::string>::const_iterator const_iterator;
+    typedef std::vector<std::string>::const_reverse_iterator const_reverse_iterator;
+
     /*!
     @brief create JSON pointer
 
@@ -75,6 +78,38 @@ class json_pointer
         return to_string();
     }
 
+    const_iterator cbegin() const
+    {
+        return reference_tokens.cbegin();
+    }
+
+    const_iterator cend() const
+    {
+        return reference_tokens.cend();
+    }
+
+    const_reverse_iterator crbegin() const
+    {
+        return reference_tokens.crbegin();
+    }
+
+    const_reverse_iterator crend() const
+    {
+        return reference_tokens.crend();
+    }
+
+    json_pointer appended(std::string const& next) const
+    {
+        json_pointer copy(*this);
+        copy.reference_tokens.push_back(next);
+        return copy;
+    }
+
+    json_pointer appended(size_t next) const
+    {
+        return appended(std::to_string(next));
+    }
+
     /*!
     @param[in] s  reference token to be converted into an array index
 

single_include/nlohmann/json.hpp

@@ -10585,6 +10585,9 @@ class json_pointer
     friend class basic_json;
 
   public:
+    typedef std::vector<std::string>::const_iterator const_iterator;
+    typedef std::vector<std::string>::const_reverse_iterator const_reverse_iterator;
+
     /*!
     @brief create JSON pointer
 
@@ -10641,6 +10644,38 @@ class json_pointer
         return to_string();
     }
 
+    const_iterator cbegin() const
+    {
+        return reference_tokens.cbegin();
+    }
+
+    const_iterator cend() const
+    {
+        return reference_tokens.cend();
+    }
+
+    const_reverse_iterator crbegin() const
+    {
+        return reference_tokens.crbegin();
+    }
+
+    const_reverse_iterator crend() const
+    {
+        return reference_tokens.crend();
+    }
+
+    json_pointer appended(std::string const& next) const
+    {
+        json_pointer copy(*this);
+        copy.reference_tokens.push_back(next);
+        return copy;
+    }
+
+    json_pointer appended(size_t next) const
+    {
+        return appended(std::to_string(next));
+    }
+
     /*!
     @param[in] s  reference token to be converted into an array index
 

test/src/unit-json_pointer.cpp

@@ -441,6 +441,47 @@ TEST_CASE("JSON pointers")
         }
     }
 
+    SECTION("iterator access")
+    {
+        SECTION("forward iterator access")
+        {
+            auto ptr = "/foo/bar/c%d"_json_pointer;
+            std::vector<std::string> components(ptr.cbegin(), ptr.cend());
+            CHECK(components.size() == 3u);
+            CHECK(components[0] == "foo");
+            CHECK(components[1] == "bar");
+            CHECK(components[2] == "c%d");
+        }
+
+        SECTION("reverse iterator access")
+        {
+            auto ptr = "/foo/bar/c%d"_json_pointer;
+            std::vector<std::string> rcomponents(ptr.crbegin(), ptr.crend());
+            CHECK(rcomponents.size() == 3u);
+            CHECK(rcomponents[2] == "foo");
+            CHECK(rcomponents[1] == "bar");
+            CHECK(rcomponents[0] == "c%d");
+        }
+    }
+
+    SECTION("appending")
+    {
+        SECTION("can append to empty string pointer")
+        {
+            auto ptr = ""_json_pointer;
+            CHECK(ptr.to_string() == "");
+
+            ptr = ptr.appended("foo");
+            CHECK(ptr.to_string() == "/foo");
+
+            ptr = ptr.appended("bar");
+            CHECK(ptr.to_string() == "/foo/bar");
+
+            ptr = ptr.appended(10);
+            CHECK(ptr.to_string() == "/foo/bar/10");
+        }
+    }
+
     SECTION("conversion")
     {
         SECTION("array")