add inplace_patch

docs/mkdocs/docs/api/basic_json/patch.md

@@ -1,25 +1,34 @@
 # <small>nlohmann::basic_json::</small>patch
 
 ```cpp
+// (1)
 basic_json patch(const basic_json& json_patch) const;
+
+// (2)
+void patch_inplace(const basic_json& json_patch) const;
 ```
 
 [JSON Patch](http://jsonpatch.com) defines a JSON document structure for expressing a sequence of operations to apply to
 a JSON document. With this function, a JSON Patch is applied to the current JSON value by executing all operations from
 the patch.
 
+1. applies a JSON patch to a copy of the current object and returns the copy
+2. applies a JSON patch in place and returns void
+
 ## Parameters
 
 `json_patch` (in)
 :   JSON patch document
 
 ## Return value
 
-patched document
+1. patched document
+2. void
 
 ## Exception safety
 
-Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
+1. Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
+2. No guarantees, value may be corruted.
 
 ## Exceptions
 

include/nlohmann/json.hpp

@@ -4641,13 +4641,11 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @name JSON Patch functions
     /// @{
 
-    /// @brief applies a JSON patch
+    /// @brief applies a JSON patch in-place without copying the object
     /// @sa https://json.nlohmann.me/api/basic_json/patch/
-    basic_json patch(const basic_json& json_patch) const
+    void patch_inplace(const basic_json& json_patch)
     {
-        // make a working copy to apply the patch to
-        basic_json result = *this;
-
+        basic_json& result = *this;
         // the valid JSON Patch operations
         enum class patch_operations {add, remove, replace, move, copy, test, invalid};
 
@@ -4911,7 +4909,14 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                 }
             }
         }
+    }
 
+    /// @brief applies a JSON patch to a copy of the current object
+    /// @sa https://json.nlohmann.me/api/basic_json/patch/
+    basic_json patch(const basic_json& json_patch) const
+    {
+        basic_json result = *this;
+        result.inplace_patch(json_patch);
         return result;
     }
 
@@ -5049,7 +5054,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
         return result;
     }
-
     /// @}
 
     ////////////////////////////////